2012 PORSCHE 911 CARRERA 911 CARRERA S 991 SERVICE MANUAL

2012 911 Section 1-1 11/3/11 10:06 AM Page U1

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®

Service Information 2012 Technik Introduction 911 Carrera/911 Carrera S (991)

Important Notice: Some of the contents of this AfterSales Training brochure was originally written by Porsche AG for its rest-ofworld English speaking market. The electronic text and graphic files were then imported by Porsche Cars N.A, Inc. and edited for content. Some equipment and technical data listed in this publication may not be applicable for our market. Specifications are subject to change without notice.

We have attempted to render the text within this publication to American English as best as we could. We reserve the right to make changes without notice. © 2011 Porsche Cars North America, Inc. All Rights Reserved. Reproduction or translation in whole or in part is not permitted without written authorization from publisher. AfterSales Training Publications Dr. Ing. h.c. F. Porsche AG is the owner of numerous trademarks, both registered and unregistered, including without limitation the Porsche Crest®, Porsche®, Boxster®, Carrera®, Cayenne®, Cayman®, Panamera®, Tiptronic®, VarioCam®, PCM®, 911®, 4S®, FOUR, UNCOMPROMISED.® and the model numbers and the distinctive shapes of the Porsche automobiles such as, the federally registered 911 and Boxster automobiles. The third party trademarks contained herein are the properties of their respective owners. Porsche Cars North America, Inc. believes the specifications to be correct at the time of printing.

Specifications, performance standards, standard equipment, options, and other elements shown are subject to change without notice. Some options may be unavailable when a car is built. Some vehicles may be shown with non-U.S. equipment. Please ask your dealer for advice concerning the current availability of options and verify the optional equipment that you ordered. Porsche recommends seat belt usage and observance of traffic laws at all times. Printed in the USA Printed in the USA

Part Number - PNA 911 021 12

Edition - 11/11

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Foreword

“The best 911 ever.” With every new generation of the sports car classic comes the expectation that it is even better than its predecessors. Attempting to make the perfect sports car even better is both an honor and an obligation. The new 911 once again succeeds in setting new benchmarks thanks to its sporty design, intelligent lightweight construction and new technologies - and is even sportier and more

0_01_11

The new 911 is the first to be completely redesigned in the last 15 years. It has grown by 2.4˝ (6 cm) to 14.75’ (4.50 m) in length. One of the most noticeable changes, however, is the 3.9˝ (10 cm) longer wheelbase, which is clearly evident in the enhanced driving dynamics and the larger cabin. Steel and aluminum have been combined in a perfectly coordinated hybrid design that has made it possible to reduce the weight of 3042 lbs (1,380 kg) by 77 lbs (35 kg) despite the increased dimensions.

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suitable for day-to-day use than its predecessor.

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The new 911 generation is available with two different engines. The 3.4-liter flat-six engine of the Carrera delivers 350 hp and has a top speed of 179 mph (289 km/h).

A regenerative brake system, demand-controlled auxiliary units, a coasting function (rolling without engine power) and Auto Start Stop contribute to a reduced fuel consumption. The new 7-speed transmission has been a significant contributing factor here. The Carrera S reaches a top speed of 188 mph (302 km/h) with its 400-hp 3.8-liter engine. In addition to the higher engine speeds for both engine variants, the new roll stabilization system and the dynamic engine mountings, which are available with the Sport Chrono package, have played a major role in reducing the lap time on the Nordschleife with the Carrera S by 13 seconds to 7 minutes and 40 seconds.

to meet the high expectations of Porsche customers, in spite of the ever increasing complexity of the technology used in the vehicles and the growing number of different variants. This Service Information brochure describes the technical modifications that have been made to the new 911 (991) generation based on the vehicles from the 2nd generation 911 (997) model years 2008 to 2012.

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A high level of qualification throughout the entire AfterSales organization is essential

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Contents

3

General

3

Technical data

4

Belt drive

6

Crankcase

6

Piston

6

Camshafts

6

Camshaft adjuster

7

Engine oil circuit

7

Cooling system

10

2 DME engine electronics

1

DME engine electronics

2

Power transmission

3

13

General

13

Technical data

15

DME control unit

17

DME diagnosis

19

Power supply

22

Fuel system

23

Intake system

27

Mixture formation

32

Ignition system

39

Exhaust system, emission control

40

Auto Start Stop function

46

Coasting function

51

Thermal energy management

53

3 Power transmission

Engine

83

General

83

Clutch

84

7-speed manual transmission

84

Technical data G91/00

84

Shift mechanism

85

Locking

89

Gearshift lock for 7th gear

91

Gear wheel set

92

Synchronization

94

Drive

95

Differential lock

95

Oil circuit

96

Neutral detection sensor

98

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1 Engine

Power transmission

Chassis

Body

3 4

5

7-speed Porsche Doppelkupplung (PDK)

99

General

99

Coasting function

99

Neutral via paddle

101

Auto Start Stop system

102

Thermal management/lubricating oil supply

103

Controlled rear differential lock (CRDL)

106

Wiring harness

107

Transmission control unit

109

Porsche Doppelkupplung (PDK)

109

4 Chassis

111

General

111

Front axle

114

Rear axle

117

Power steering

119

Dynamic engine mountings

127

Porsche Active Suspension Management

130

Porsche Dynamic Chassis Control

133

Wheels and tires

140

Tire pressure monitoring

141

Brake system

143

Electric parking brake

144

Porsche Stability Management

148

Porsche Torque Vectoring

153

5 Body

155

General

155

Unpainted bodyshell

157

Aerodynamics

162

Slide/tilt roof

165

Exterior mirrors

166

Roof transport system

166

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911 Carrera 911 Carrera S

169

General

169

Front and side view

170

Rear view

171

Occupant protection

172

Cupholders

176

Glove compartment

176

Oddments tray

177

Luggage compartment lid and engine cover

178

Sun visor

179

7 Body - Interior equipment

181

New operating concept

181

Steering wheel

182

Seats

183

New Porsche key

185

Luggage compartment and storage

186

Body - Interior equipment

7

189

General

189

Ventilation

190

Operation

195

Refrigerant circuit

205

Actuators and sensors

207

Topology of the air-conditioning system

210

9 Electrics and electronics

6

181

General

8 Heating and air conditioning

Body exterior

Heating and air conditioning

8

Electrics and electronics

9

213

General

213

Vehicle electrical system/energy management

214

Auto Start Stop function

226

Lighting

227

Front-end electronics control unit

235

Rear-end electronics control unit

242

Instrument cluster

244

ParkAssist

246

Infotainment

248

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6 Body exterior

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911 Carrera 911 Carrera S

1 Engine

1.1 General Two different engines are available for the 911 Carrera (991). The standard models come with an engine where the displacement has been reduced (to 3.4 liters from

Engine

the previous 3.6 liters) but the high torque of the previous engine has been retained and the power increased further. This has been made possible by increasing the

1

nominal rpm from 6,500 rpm to 7,400 rpm.

The S models still come with a 3.8-liter engine. Here the power has been increased by 15 hp to 400 hp (294 kW). As with the 3.4-liter engine, the nominal rpm have been increased to 7,400 rpm (+ 900 rpm) and the maximum engine speed has been increased to 7,800 rpm (+ 300 rpm). The maximum torque is now 440 Nm

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(+ 20 Nm).

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On the following pages you will find details of the technical data, followed by a description of the changes to the individual components of the engine compared with the 2nd generation 997.

General

3

Technical data

4

Belt drive

6

Crankcase

6

Piston

6

Camshafts

6

Camshaft adjuster

7

Engine oil circuit

7

Cooling system

10

3

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911 Carrera 911 Carrera S

Engine

1.2 Technical data

1

Full load curves for the 3.4-liter engine MA104

3.4 l

[Nm]

[rpm] 1_02_11

Technical engine specifications

4

Number of cylinders

6

Valves per cylinder

4

Displacement

3,436 cm3

Bore

97 mm

Stroke

77.5 mm

Power

350 hp (257 kW)

at engine speed

7,400 rpm

Max. torque

288 ft lb (390 Nm)

at engine speed

5,600 rpm

Compression ratio

12.5

Intake-valve lift, small

3.6 mm

Intake-valve lift, large

10.5 mm

Exhaust valve lift

10.35 mm

Governed speed

7,800 rpm (6,300 rpm cold)

Engine weight, MT/PDK

432 lbs (196 kg)/423 lbs (192 kg)

Cylinder firing order:

1-6-2-4-3-5

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[Nm]

[kW]

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911 Carrera 911 Carrera S

Full load curves for the 3.8-liter engine MA103 Engine 3.8 l

[Nm]

1

[rpm] 1_03_11

Technical engine specifications Number of cylinders

6

Valves per cylinder

4

Displacement

3,800 cm3

Bore

102 mm

Stroke

77.5 mm

Power

400 hp (294 kW)

at engine speed

7,400 rpm

Max. torque

325 ft lb (440 Nm)

at engine speed

5,600 rpm

Compression ratio

12.5

Intake-valve lift, small

3.6 mm

Intake-valve lift, large

11.0 mm

Exhaust valve lift

11.0 mm

Governed speed

7,800 rpm (6,300 rpm cold)

Engine weight, MT/PDK

432 lbs (196 kg)/423 lbs (192 kg)

Cylinder firing order:

1-6-2-4-3-5

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[Nm]

[kW]

5

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911 Carrera 911 Carrera S

1

Because the 911 Carrera (991) features electromechanical steering, the servo pump on the engine is no longer required. If the vehicle is equipped with the optional PDCC system, the hydraulic pump for this system is located at this position.

1_06_11

1.4 Crankcase The crankcase has been adopted from the predecessor engine with only minor changes in the following areas: • Attachment point for the engine strut • Attachment point for the coolant pump • Omission of the lifting eyebolt 1_04_11

The reason for these changes is the increased load at the attachment points (see arrows in Fig. 1_04_11).

1.5 Piston Precision milling is used on the piston in the groove for the oil scraper ring as a means of effectively improving emissions stability (see arrow in Fig. 1_05_11).

1.6 Camshafts Assembled camshafts are used on the 911 Carrera (991). An assembled camshaft is a camshaft on which the cams are manufactured separately from the shaft body 1_05_11

6

and are subsequently attached permanently to the shaft body.

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Engine

1.3 Belt drive

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911 Carrera 911 Carrera S

1.7 Camshaft adjuster Both engine versions are still equipped with VarioCam Plus, the adjustment range is now 50° crank angle. The vane adjuster has an aluminum housing in order to

Engine

optimize weight.

1

1.8 Engine oil circuit Variable oil pump As on the predecessor, the engine oil pressure is supplied via a variable oil pump.

This means that the correct oil quantity and the correct oil pressure are always delivered.

harm, it has been possible to dispense with the following seals on the oil pump compared with the predecessor:

1_07_11

• Round seals on the oil extraction pumps • O-ring on the pressure outlet This has also allowed machining of the groove to be dispensed with.

Further changes are the asymmetric strainer and omission of the holder (see Figs.

1_07_11 and 1_08_11).

Oil level measurement The 911 Carrera (991) provides the option of performing a dynamic oil level measurement when the vehicle is moving and a static measurement without the engine running when the vehicle is stationary.

If a display is shown in the instrument cluster then it is valid in principle.

The measuring options described below are possible due to the integrated dry-sump lubrication of the engine and the associated structure of the oil pan and sensor.

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Since only internal leaks can occur in the oil pump and these do not cause any

1_08_11

!

Engine oil must only be added when the engine is switched off.

The engine is filled with approx. 10.6 qts (10 liters) of engine oil, the change quantity is approx. 7.9 qts (7.5 liters).

When the rear lid is open, the engine-oil level in the instrument cluster is only updated when the engine is switched off.

When the rear lid is open and the engine is running, the oil level is not updated, i.e. the engine can be overfilled.

7

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911 Carrera 911 Carrera S

1

Engine

Oil sensor The sensor consists of an ultrasonic sensor with an integrated evaluation unit and a temperature sensor for detecting the engine oil temperature.

A measuring cup with an inlet hole at the bottom and a vent hole at the top is placed over the ultrasonic sensor.

A meander-shaped element is used at the inlet hole to permit an accurate measurement.

Dynamic measurement Conditions for recalculation:

• Engine running Oil level OK, 100%

1_09_11

• Oil temperature at the sensor > 158° F. (70° C.) • Engine speed < 2,500 rpm • Longitudinal and lateral acceleration < 1 m/s2, and tilt angle < 5.7° When the vehicle is stationary, the measurement is completed within 2 to 3 minutes, depending on the inclination of the vehicle. The measurement is completed within approx. 3 to 9 miles (5 to 15 km) while driving, depending on driving style. The measured values are only used for calculation if the conditions are met. The result is then displayed in the instrument cluster via CAN. This value can also be displayed in the instrument cluster when the ignition is on.

Oil level OK, 75%

1_10_11

Static measurement Conditions for recalculation: • Engine off • Oil temperature at the sensor > 158° F. (70° C.) • Longitudinal and lateral acceleration < 1 m/s2, and tilt angle < 5.7° • Wait max. 60 seconds When the ignition is switched on, the result is then transmitted to the instrument cluster via CAN and displayed after 2.5 seconds.

Oil level OK, 50%

1_11_11

The following applies to both measurements: If the conditions are not met when the measurement is performed, the last valid value will be displayed.

A mean value calculated from the static measurement and dynamic measurement is displayed.

If there is no dynamic measurement, the static measurement value is always displayed.

Oil level OK, 25%

8

1_12_11

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• Rear lid closed

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911 Carrera 911 Carrera S

Oil level measurement after opening the engine compartment lid When the engine compartment lid is opened for more than 45 seconds, all previously determined measured values are discarded because the DME control

Engine

unit assumes that oil was added.

1

The oil level is no longer displayed in the instrument cluster and the message "Display only possible after short time" appears.

A new static value is measured 60 seconds after switching off the engine (engine

Engine compartment opened > 45 seconds = oil level value reset Static measurement (engine off)

min oil level reached

1_13_11

Oil level below min

1_14_11

Oil level above max

1_15_11

Dynamic measurement (engine running)

Hot > 158° F. (70° C)

• Engine off for approx. 60 seconds • Ignition on

• Oil return

• • •

No minimum distance Measurement even when vehicle stationary Number of valid measured values >X

Compensation for inclined position

Return flow map (engine off time, oil temperature)

Compensation for inclined position

Static oil level

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oil temperature > 158° F./70° C.) even if the ignition is switched off.

Dynamic oil level

Calculation of a mean value

Conversion to %

Output to instrument cluster

9

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911 Carrera 911 Carrera S

Engine

1

1.9 Cooling system

An additional center radiator is available as optional equpment for extremely hot

The coolant expansion tank is located in the service opening under the engine

countries.

compartment lid, on the left in the direction of travel. There are two caps on the tank, both of which are black for reasons of appearance.

The left-hand cap is for coolant, while the right-hand cap is used as an oil filler opening. The caps themselves are identified with appropriate symbols. The two threads are different to avoid interchanging.

!

The coolant quantity can vary between 30.3 and 32 qts (28.7 and 30.3 liters) depending on equipment.

1_17_11

The red ball indicates the current coolant level. This ball must be in the area between the min and max markings (Fig. 1_19_11) when the engine is cold and 1_19_11

10

the vehicle is positioned horizontally.

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1_16_11 1_18_11

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911 Carrera 911 Carrera S

2 DME engine electronics

2.1 General An enhanced engine generation based on the DFI (direct fuel injection) engines familiar from the previous models is used for the 911 Carrera (991) models. By

DME engine electronics

improving efficiency and using the latest engine technology, it has been possible to bring about a further significant reduction in the fuel consumption values for

2 cardiagn.com

the 3.4-liter and 3.8-liter engines compared with the previous models.

2_401_11

The focus in this chapter is on the principle new features of the 911 Carrera (991) compared with the previous model (997).

General

13

Auto Start Stop function

46

Technical data

15

Coasting function

51

DME control unit

17

Thermal energy management

53

DME diagnosis

19

Power supply

22

Fuel system

23

Intake system

27

Mixture formation

32

Ignition system

39

Exhaust system, emission control

40

13

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911 Carrera 911 Carrera S

DME engine electronics

2

Development goals for the engine The characteristics that are typical of the 911 Carrera, such as superior driving dynamics and performance combined with low fuel consumption, low CO 2 emissions and exceptional day-to-day usability, have been further improved.

Increase in engine power • + 5 hp for the 911 Carrera (3.4-liter) • + 15 hp and + 20 Nm for the 911 Carrera S (3.8-liter)

Reduced fuel consumption and emission values • Reduced by 8 to 15%, depending on the model.

Doppelkupplung (PDK), for example, have been reduced by 15%.

In addition to direct fuel injection (DFI), which was introduced to sports cars with 2_402_11

the 911 Carrera (997) and has already allowed improvements in fuel economy compared with the previous models, the new flat-six engines feature the following new technologies: • Thermal management for engine, transmission and heating • Auto Start Stop function • Variable deceleration fuel cutoff • Vehicle electrical system recuperation (- 0.1 liters in NEDC - New European Driving Cycle) • Displacement downsizing on the 911 Carrera (- 0.2 liters) • Coasting in conjunction with 7-speed Porsche Doppelkupplung (PDK) • 7-speed manual transmission (+ 1 gear) • Electromechanical power steering (- 0.1 liters)

Performance/driving dynamics • Sport button as standard • Sport Chrono package incl. dynamic engine mountings (optional)

General changes to the DME The new engines use new 6 hole injectors compared to previous models. These ensure more efficient mixture formation, smoother running and maximum power output.

The flow resistance has been reduced by optimizing the air cleaner and air cleaner housing.

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• Fuel consumption and emission values on the 3.4-liter Carrera with Porsche

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911 Carrera 911 Carrera S

The intake system has been derestricted by omitting the hot-film mass air flow sensor in the intake tract and using a pressure sensor for load detection on the intake manifold instead.

DME engine electronics

The exhaust system has also been derestricted by optimizing flow characteristics

2

in order to reduce exhaust backpressure.

The new thermal management system also helps to reduce emissions and fuel consumption through controlled heating of the engine and transmission.

3.4-liter engine Displacement has been reduced from 3.6 liters to 3.4 liters by reducing the stroke from 81.5 mm to 77.5 mm.

Nominal revs have been increased to 7,400 rpm and the maximum engine speed to 7,800 rpm in order to increase power output by + 5 hp despite the reduction in displacement.

Engine specifications for the 3-4-liter DFI (MA 104)

3.4 l

[Nm] [kW]

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2.2 Technical data

Displacement

3,436 cm3

Engine power

350/257 hp/kW

[Nm]

at 7,400 rpm Engine torque

288 ft lb (390 Nm) at 5,600 rpm

Compression ratio

12.5 : 1

Idle speed

680 +/- 25 rpm

Max. engine speed

7,800 rpm

[rpm] 1_02_11

15

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911 Carrera 911 Carrera S

DME engine electronics

3.8-liter engine

2

On the Carrera S, the nominal revs have been increased to 7,400 rpm and the maximum engine speed to 7,800 rpm in order to increase power output by + 15 hp.

The engine torque has been increased by 15 ft lb (20 Nm).

The 3.8-liter engine also has a tuning flap in the intake manifold for improved charging, high torque at low to medium rpm and an even torque curve. In addition, the 3.8-liter engine has a flap exhaust system in order to increase engine power by further reducing exhaust backpressure at high rpm.

Displacement

3,800 cm3

[Nm]

Engine power

400/294 hp/kW

[kW]

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Engine specifications for the 3.8-liter DFI (MA 103)

3.8 l

Engine torque

325 ft lb (440 Nm)

[Nm]

at 7,400 rpm at 5,600 rpm Compression ratio

12.5 : 1

Idle speed

680 +/- 25 rpm

Max. engine speed

7,800 rpm

[rpm] 1_03_11

16

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911 Carrera 911 Carrera S

2.3 DME control unit The DME control unit Continental SDI 9 is installed at the top right of the engine compartment; the wiring harness is routed directly to the engine without any connection points.

DME engine electronics

2

The high-performance electronic engine control unit EMS SDI 9 from Continental is used for the 911 Carrera (991) engines. This control unit has been specially designed to meet the requirements for use of direct fuel injection (DFI) and VarioCam Plus. Of particular significance here is control of the injectors, which are central elements of the direct fuel injection system. The engine control also controls the throttle position (electronic throttle) as this is a prerequisite for the Porsche

The modern DME control unit allows sequential injection of fuel into the combustion chamber for each cylinder at precisely defined time intervals. This helps to minimize fuel consumption and reduce emissions, even during dynamic driving. Each cylinder receives precisely the amount of fuel that corresponds to the engine load condition in order to achieve an optimum air/fuel ratio.

Brief overview of DME features New DME components • 6 hole injectors • Differential Hall-effect sensor on the crankshaft • Pressure sensor on the intake manifold for load detection • Tank leakage diagnostic system (NVLD) for USA vehicles

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Stability Management (PSM) system installed as standard.

2_405_11

New functions of the DME control unit • Thermal management • Auto Start Stop function (Porsche Doppelkupplung [PDK] and manual transmission) • Coasting (vehicles with Porsche Doppelkupplung [PDK] only) • Variable deceleration fuel cutoff

2_406_11

• Vehicle electrical system recuperation

17

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911 Carrera 911 Carrera S

DME engine electronics

2

General overview of DME functions • Thermal management • Auto Start Stop function • Variable deceleration fuel cutoff • Vehicle electrical system recuperation • Direct fuel injection (DFI) • Low-pressure fuel supply • Returnless fuel system • High-pressure fuel supply (quantity control valve) • Electronic throttle • Electronic throttle with idle speed control

2_407_11

• Demand-controlled variable oil pump • Switchable resonator on the air cleaner housing • Tuning flap on the intake system (Carrera S only) • Intake system sound symposer • Stereo lambda control circuits • Flap control on the intake system (Carrera S and sports exhaust system) • Static high-voltage ignition distribution (individual ignition coils with integrated drivers) • Cylinder-specific knock control (with 2 knock sensors) • 2 electric radiator fans (continuously variable) • 2 engine compartment purge fans (2-stage) • Differential Hall-effect sensor (detects engine speed, reference mark and direction of rotation of the engine • Pressure sensor on the intake manifold (detects intake manifold pressure and intake air temperature) • On-board diagnosis for monitoring the emission control system

CAN networking In addition to the sensors and actuators that are connected directly to the DME control unit, the DME control unit also has access to other data, which is assigned to other control units as input or output variables. This external data is accessed via the internal high-speed network, the so-called CAN (Controller Area Network) bus.

18

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• VarioCam Plus (intake camshaft)

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911 Carrera 911 Carrera S

2.4 DME diagnosis The DME control unit Continental SDI 9 can be programmed with the data records for the relevant emission standards, for example EURO 4 (EOBD), EURO 5 (EOBD), USA LEV II (OBD II), on a country-specific basis.

DME engine electronics

2

The DME control unit EMS SDI 9 provides the following new DME diagnostic functions and sequences on PIWIS Tester II, for example: • Actual values, for example for thermal management and Auto Start Stop system • System test for vacuum system • System test for thermostat

• New short tests (more user-friendly and with F1 – help)

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• Bleeding the cooling system 2_408_11

Further DME diagnostic information can be found in PIWIS Tester II under: • F1 – help (context-sensitive help) • as well as in Guided Fault Finding/Components and functions/Drive/General information

Actual values The following new function groups are available under the DME actual values: • T_Temperatures Actual values for thermal management.

• ST_Start Stop Actual values for the Auto Start Stop system.

• LV_Short test results

2_407_11

If the ignition was not switched off after performing a test drive (the vehicle is still running), you can see which short tests have already been carried out for this driving cycle under the DME actual values “LV_Short test results”.

In this case, it is sufficient to carry out the outstanding short tests in order to achieve the Ready status for all OBD-relevant systems.

Only once all systems have achieved the Ready status can it be established whether these are OK by checking the fault memory.

19

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911 Carrera 911 Carrera S

DME engine electronics

2

Maintenance/repair • Short tests Particular attention must be paid to the new and modified preconditions, for example “Engage parking brake”, during the short tests.

The new, user-friendly short tests mean the Ready status can be achieved in the workshop for almost all OBD-relevant systems (exception: Fuel supply part load).

Increased rpm of up to max 1,500 rpm are activated by the Tester, for example, without pressing the accelerator pedal; in the case of higher speed demands, this is displayed on the Tester using the information for the relevant short test.

Note: The passive tank leakage diagnostic system NVLD (Natural Vacuum Leak

purpose.

2_408_11

• System tests Particular attention must be paid to the preconditions, for example “Engage parking brake”, during the system tests.

• System test for vacuum system The engine speed is increased to approx. 1,500 rpm. All solenoid switch-over valves are opened or closed at the same time.

Diagnosis: Phase 1 (leak test) All solenoid switch-over valves are opened at the same time.

2_407_11

The PIWIS Tester prompts you to press the brake pedal several times and then wait with the pedal not pressed. A test is performed using the brake vacuum sensor to check whether the pressure in the system has dropped below a certain value within a certain time period.

Phase 2 (exchange test) All solenoid switch-over valves are opened at the same time. The PIWIS Tester prompts you to press the brake pedal several times and then wait with the pedal not pressed. A test is performed using the brake vacuum sensor to check whether the pressure in the system has dropped below a certain value within a certain time period. The result is displayed when diagnosis is complete: The result could indicate, for example, that the vacuum lines were not connected correctly to one or more solenoid switch-over valves (supply line to the working connection and vice versa).

Test duration approx. 2 to 4 minutes.

20

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Detection) is installed for USA. A short test is not therefore required for this

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911 Carrera 911 Carrera S

System test for map-controlled thermostat • The engine speed is increased to approx. 1,500 rpm. The electric radiator fans are activated fully after some time.

The diagnostic system checks the function of the engine temperature sensor and thermostat by measuring the engine temperature (T020) and the radiator

DME engine electronics

2

outlet temperature (T025). It takes into consideration maximum times until the required temperatures are reached.

The thermostat and both radiator fans are specifically activated for this purpose.

Test sequence Phase 1 - Prepare for the test (allow the system to heat up, engine tempera-

Phase 2 - Set test conditions (engine temperature must reach a minimum value) Phase 3 - Test thermostat closing function (engine temperature must maintain a minimum value) Phase 4 - Test thermostat electrical opening function (engine temperature must fall significantly).

Test duration approx. 5 to 25 minutes.

• Bleeding the cooling system Always follow the instructions on the PIWIS Tester.

Before starting to bleed the cooling system, fill the system as described in the Workshop Manual.

This function in the PIWIS Tester “opens” and “closes” the thermal management valves in a targeted manner and guides the mechanic through the

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ture [T020] approx. 176 to 248° F. (80 to 120° C.).

2_408_11

2_407_11

bleeding process by displaying instructions on the PIWIS Tester.

Note: This function is the only way to successfully bleed the cooling system.

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911 Carrera 911 Carrera S

DME engine electronics

2

2.5 Power supply Fuse carriers: The 911 Carrera (991) has fuse carriers at the left and right A-pillars in the footwell and on relay carrier 2 behind the right rear seat.

The fuse for the electric fuel pump is installed on the fuse carrier in the left footwell (Fig. 2_409_11).

Relay carrier 1: The relay for the electric fuel pump is installed on relay carrier 1 (Fig. 2_410_11, 1), which is located on the left A-pillar, above the fuse carrier (3).

Most fuses and relays relating to the DME are located on relay carrier 2 (Fig. 2_411_11, 2), which can be found behind the right rear seat, under the shelf.

The exact assignment of the fuse carriers and relay carriers and the assignment of sensors and actuators to the DME control unit can be found in the corresponding wiring diagram on PIWIS Tester II and in the PIWIS information system.

Function overviews For the engine, the wiring diagram contains the following “function overviews” 2_409_11

relating to CAN networking: • Measuring and displaying coolant temperature • Engine speed • Controlling and monitoring oil pressure • Monitoring and displaying oil level • Starting the combustion engine • Measuring and displaying fuel level • Controlling flap exhaust system

2_410_11

2_411_11

22

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Relay carrier 2:

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911 Carrera 911 Carrera S

2.6 Fuel system Fuel supply, low-pressure side The engine is designed to provide optimum performance and fuel consumption if premium unleaded fuel 93 octane (

R+M 2

DME engine electronics

) is used. The engine is suitable for operation

with fuel containing up to 10% ethanol. The use of fuels containing ethanol can

2

result in increased fuel consumption.

If unleaded fuel with 90 octane ( R+M 2 ) or less is used, the engine’s knock control automatically adapts the ignition timing.

The use of unleaded fuel with octane numbers of less than 90 octane ( R+M 2 ) could

at full throttle.

Fig. 2_412_11 C2 fuel tank, 16.9 gal. (64 liters), 2.6 gal. (10-liter) reserve Carbon canister (not for USA) Installation position of the control unit for the electric fuel pump flow control under the battery retaining bracket.

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reduce engine power and increase fuel consumption. The vehicle must not be driven

2_412_11

Special tool 9731 1 The special tool 9731 1 (Fig. 2_413_11) is used for opening the fuel tank cap on the top of the fuel tank (Fig. 2_414_11, 1).

Control unit for electric fuel pump

9731 1

The control unit for electric fuel pump flow control (Fig. 2_416_11, 2) is installed under the battery tray (3). Depending on the amount of fuel required, the current consumption on Carrera 2 vehicles, and thus the delivery rate of the electric fuel pump, is controlled at a level between 6 and 15 amps. The current consumption

2_413_11

can be measured at the fuse of the electric fuel pump.

2_416_11

2_414_11

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911 Carrera 911 Carrera S

DME engine electronics

2

Returnless fuel system The 911 Carrera 2 (991) features a returnless fuel system. On the low-pressure side, the electric fuel pump installed in the swirl pot delivers the fuel to the 3-piston high-pressure pump via the fuel filter and fuel pressure regulator (approx. 72.5 psi/ 5 bar).

! in the PIWIS information system Group 2 must be observed when working on the fuel system.

2_417_11

1

Tank filler neck

2

Surge flap

3

Swirl pot with electric fuel pump

4

Fuel filter with fuel pressure regulator

5

Fuel-level sensor

The procedure for checking the fuel

6

Fill-level control valve

pressure, holding pressure and fuel

7

Control unit for electric fuel pump

delivery rate is described in the PIWIS

8

Electric lines

information system Group 2.

9

Low-pressure fuel line (approx. 72.5 psi/5 bar) to high-pressure pump

10

Engine

11

Tank ventilation to carbon canister

!

24

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The specifications and safety instructions

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911 Carrera 911 Carrera S

Fuel supply, high-pressure side The fuel high-pressure system is largely the same as that of the previous 997 Carrera model.

DME engine electronics

Unlike the 997 DFI engines, which are equipped with swirl injectors, the 991 vehicles

2

use six hole injectors with a softer clip.

The electric fuel pump in the fuel tank delivers the low-pressure fuel via the quantity control valve (see Fig. 2_419_11, 1.1) at approx. 72.5 psi (5 bar), directly into the 3-piston high-pressure pump (see Fig. 2_418_11, 1). The high-pressure pump driven by the camshaft delivers the fuel high pressure (approx. 580 to 1740 psi/40 to 120

via the connecting lines (3) when the engine is running. The fuel high-pressure sensor (5) is located in the right fuel rail.

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bar) to the fuel rails (4) on the left and right cylinder banks and to the injectors (6)

2_419_11

2_418_11

1

Fuel high-pressure pump (3 pistons) with quantity control valve (1.1)

2

High-pressure supply line

3

Connecting line (banks 1 and 2)

4

High-pressure rail

5

Fuel high-pressure sensor

6

Injectors (6 holes, with soft clip)

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911 Carrera 911 Carrera S

DME engine electronics

2

Injectors New fuel injectors with 6 holes are used to ensure more efficient mixture formation, smoother running and maximum power.

Figure 2_420_11 shows a 6 hole injector on the right and a swirl injector on the left.

The 3.4-liter and 3.8-liter engines use injectors with a different injection mass. The engine-specific assignment of the injectors is via the part number as well as a coloured identification clip (see Fig. 2_422_11, 1) on the injector. Figure 2_423_11

2_420_11

2_422_11

2_423_11

Injector holder clip Fig. 2_421_11: Using a softer clip to hold the injector dampens the noise made by the injector when closing.

This is necessary because the modified thermodynamics resulting from the 6 hole injectors means that knock detection reacts very sensitively in the rpm range under 3,000 rpm.

2_421_11

26

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shows the 6 hole injector.

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911 Carrera 911 Carrera S

2.7 Intake system

2

Air guide The dual-branch air guide (see Fig. 2_424_11, 1) from the engine cover to the air

DME engine electronics

cleaner housing has optimized/derestricted this area of the intake system.

Sound opening The mesh on the sound openings (2) allows the intake sound to travel into the engine compartment, but prevents warm air from the engine compartment from being sucked in.

Fig. 2_424_11 to 2_426_11 1

Two-branch air guide from the air intake on the engine cover to the

2

Sound openings at the bottom and top of the air cleaner housing

3

Silencer (resonator) in the air cleaner housing

4

Diaphragm cell between the intake and silencer in the air cleaner housing

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air cleaner housing

2_424_11

on both engines 5

Flap in the air cleaner housing silencer

Silencer Both engines have a silencer (resonator) in the air cleaner housing that is activated

2_425_11

via a flap.

Switching points of the flap on the 3.4-liter and 3.8-liter engines: The resonator is closed for the most part, it is open between 4,500 and 6,000 rpm (irrespective of button pressed or load).

5

4 2_426_11

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911 Carrera 911 Carrera S

2

The flow-optimized air cleaner housing and the two air-cleaner elements result in higher volumetric efficiency of the engine at full load.

2_428_11

2_427_11

Sound symposer

!

The 911 Carrera models (991) are equipped with the new sound symposer as

Maintenance: The country-specific change

standard for the first time for a more emotive driving experience. This passive

intervals for the air-cleaner elements can

sound transmission system produces an even richer and sportier engine sound in the

be found in the PIWIS information

passenger compartment and can be activated and deactivated via the standard

system/maintenance schedule.

Sport button.

1

Sound symposer (acoustic simulator)

2

Control flap (vacuum-controlled)

3

Diaphragm (amplifies the vibrations)

4

Passenger compartment inlet at the rear shelf

5

Intake noise transmission into the passenger compartment

6

Unfiltered air intake

7

Air cleaner

8

Throttle valve (electronic throttle)

9

Engine, intake system

28

2_429_11

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DME engine electronics

Air cleaner housing and air cleaner

2012 911 Section 2-2 11/3/11 10:15 AM Page 29

911 Carrera 911 Carrera S

The sound symposer is a passive system for transmitting engine noise into the passenger compartment. In other words it does not generate an artificial engine sound, but rather amplifies the unique sporty sound of the 911 Carrera flat engines

DME engine electronics

and directs it into the passenger compartment at the push of a button.

2

The sound symposer is located within the intake tract of the engine and is installed between the throttle valve and air cleaner. It is connected with the passenger compartment out of the customer’s sight via a line in the area of the rear shelf. The engine’s load-dependent intake pulses cause the diaphragm integrated in the sound symposer to vibrate; the diaphragm amplifies these vibrations before they are

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transmitted directly into the passenger compartment as sound via the line.

2_431_11

2-

Control flap (vacuum-controlled)

3

Diaphragm (amplifies the vibrations)

4

Passenger compartment inlet at the rear shelf

6

Unfiltered air intake

10

Switching valves for sound

symposer and silencer (resonator in the air cleaner housing)

2_430_11

Sound symposer switching strategy The sound symposer can be electropneumatically activated or deactivated via an controllable flap located upstream of it.

With the standard exhaust system, the control flap (see Fig. 2_431_11 and 2_430_11, 2) is opened by pressing the Sport button. With the Sports exhaust system, the control flap is opened when the exhaust system button is pressed.

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911 Carrera 911 Carrera S

DME engine electronics

2

Intake manifold, pressure sensor On the 991 vehicles, the engine load is detected downstream of the electronic throttle by the pressure sensor (see Fig. 2_432_11 and 2_433_11, 2) on the intake manifold.

The derestriction of the intake system means that the intake manifold pressure at full load (throttle valve fully open, dependent on the engine speed) is approximately

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in the -20 mbar range relative to the ambient pressure.

2_433_11

2_432_11

1

Throttle housing (electronic throttle)

2

Pressure sensor for detecting the engine load and intake air temperature

3

Diaphragm cell and tuning flap on the air distributor (Carrera S only)

4

Resonance chamber in the intake distributor

Tuning flap, Carrera S The 3.8-liter engine also has a tuning flap for greater volumetric efficiency and a high torque at low to medium rpm as well as an even torque curve. The tuning flap 2_434_11

of the Carrera S is closed by the electropneumatic switching valve between 3,000 and 5,000 rpm by applying a vacuum to the diaphragm cell.

30

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911 Carrera 911 Carrera S

Pressure sensor for load detection As on the 997 Turbo DFI, the current V8 engines and the Panamera V6, using a pressure sensor to detect the engine load at the intake manifold derestricts the intake section compared with the vehicles with hot-film mass air flow sensor. This sensor also measures the temperature of the intake air.

DME engine electronics

2

Advantages of the pressure sensor for detecting the engine load: • Increased power as a result of derestriction of the intake section • Greater precision at low air-flow rates • Enhanced resistance to soiling

Voltage characteristic of an intake manifold pressure sensor as a function of intake

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manifold pressure.

2_435_11

V

h Pa

P 2_436_11

Supply voltage of the pressure sensor = 5 volts P - Intake manifold pressure (absolute pressure in mbar) V - Signal voltage in volts

31

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911 Carrera 911 Carrera S

DME engine electronics

2

2.8 Mixture formation Mixture adaptations The mixture adaptations of cylinder banks 1 and 2 for the ranges RKAT (near-idling range), FRAU (lower load/engine speed range) and FRAO (upper load/engine speed range) are the same as for the previous model.

Injection strategies Starting (inhomogeneous): Triple injection during the compression stroke (for emissions reasons when the engine is cold and to reduce knocking when the engine is warm).

Twice during the intake stroke and once during the compression stroke (with ignition point at 18° crank angle after TDC).

Engine warm (homogeneous, only during the intake stroke): Idle speed: Single injection Acceleration under load, Carrera 3.4-liter: Double injection up to an engine speed of 3,500 rpm Above this engine speed: Single injection Acceleration under load, Carrera S 3.8-liter: Double injection up to an engine speed of 3,500 rpm (under full load: triple injection up to 2,000 rpm) Above this engine speed: Single injection

Variable deceleration fuel cutoff The variable deceleration fuel cutoff is an enhancement of the conventional deceleration fuel cutoff. In principle, this involves controlled interruption of the fuel supply in driving situations where the combustion engine is not required to output any power but is kept moving by the inertia mass of the vehicle (deceleration, e.g. when driving downhill). Compared with the usual deceleration fuel cutoff systems, which resume fuel injection as from a fixed engine speed, variable deceleration fuel cutoff systems resume fuel injection flexibly depending on the driving situation, which may correspond to an even lower engine speed. Depending on the driving situation, fuel injection can resume even later, thereby saving fuel.

32

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Catalytic converter heating (inhomogeneous):

2012 911 Section 2-2 11/3/11 10:15 AM Page 33

911 Carrera 911 Carrera S

Carbon canister with tank leakage diagnosis For the first time at Porsche, the 991 vehicles intended for the USA feature the NVLD (Natural Vacuum Leak Detection) system for tank leakage diagnosis.

DME engine electronics

With this system, tank leakage diagnosis is performed as a passive long-term test when the vehicle is stationary for an extended period, which means that no short

2

test is now required for this purpose.

On vehicles with NVLD, the DME actual value “E010” indicates whether the tank system was leak-free during the most recent long-term test in the stationary vehicle.

1 DME control unit 2 NVLD evaluation unit with temperature sensor

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2_452_11

3 NVLD module (pneumatic part) 4 Carbon canister 5 Tank vent line 6 Tank vent valve

7 Throttle valve (electronic throttle)

2_439_11

Components and function The NVLD system consists of an NVLD evaluation unit (see Fig. 2_439_11, 2 electronic part with temperature sensor) and an NVLD module (3 - pneumatic part).

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911 Carrera 911 Carrera S

DME engine electronics

2

Evaluation unit The installation position of the evaluation unit is directly above the fuel tank (see Fig. 2_440_11, 5), underneath the battery tray (6). The following components (electronic part, Fig. 2_442_11, 2) are also installed here: • Temperature sensor • Evaluation unit (self-diagnosing) with: – Timer – Memory

2_440_11

1

Carbon canister for USA (installed in front of the battery)

2

NVLD evaluation unit with temperature sensor (installed under the battery holder)

3

NVLD module (pneumatic part)

4

Ventilation filter

5

Fuel tank

6

Battery tray

The NVLD evaluation unit is connected to the switch in the NVLD module via a two-wire cable.

It is supplied externally with 12 volts and ground (terminal 30 + 31).

The third external connection on the NVLD evaluation unit is the communication line which is connected to the DME control unit.

2_441_11

2_442_11

34

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– Communication interface with the DME control unit

2012 911 Section 2-2 11/3/11 10:15 AM Page 35

911 Carrera 911 Carrera S

Operating principle The leak test is performed on the basis of Amontons’ Law (the Gas Law), which states that pressure is proportional to temperature in a closed system. This means

DME engine electronics

that a change in pressure can be deduced from a change in temperature.

2

The system is sealed gas-tight (unlike previous methods) after the engine is switched off. This means that a change in temperature in the system will have a

The fuel tank ventilation system can be

direct effect on the pressure.

regarded as being leak-free if all leaks together correspond to a leak with a

The system is leak-free if a drop in temperature (long-term cooling) causes the

diameter of max. 0.4 mm (=0.016

pressure in the fuel tank to fall below -2.5 mbar relative pressure (vacuum relative to

inches).

The system is also leak-free if the

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ambient pressure).

pressure in the fuel tank after the engine

No-Leak Example

1

Pressure

is switched off is below -2.5 mbar relative pressure and this vacuum is maintained for at least 20 minutes.

Figure 2_444_11 shows the long-term

2

Temperature

Tank pressure Reacts to Change in Temperature

test for a leak-free system.

1 Pressure curve in the tank system

Engine Cool Down and Other Environment Effects

(red) 2 Temperature (blue) 3 Time

3 Time

2_444_11

Figure 2_445_11 shows the long-term test for a system with a leak.

1

Pressure

Ø 0.5 mm Leak Example

2

Temperature

No significant Change in Pressure Occurs

Engine Cool Down and Other Environment Effects

3 Time

2_445_11

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911 Carrera 911 Carrera S

DME engine electronics

2

NVLD module (pneumatic part), operating principle under vacuum This component (see Fig. 2_446_11) is located directly on the carbon canister.

Figure 2_447_11 shows a leak-free system with the switching point of the vacuum switch at -2.5 mbar.

If long-term cooling causes a vacuum (1) of -2.5 mbar in the fuel tank after the vehicle is switched off, the diaphragm (4) moves upwards and closes the switch (3).

The electric vacuum switch (3) is actuated by vacuum when the diaphragm is

2_446_11

1 Vacuum (light blue) 2 Atmosphere (blue) 3 Switch (switching point -2.5 mbar; in Fig. 2_447_11) 4 Diaphragm 5 Conical seal

2_447_11

NVLD: Mechanical Function – Vacuum at -6.0 mbar

No. 6 (see Fig. 2_448_11) shows a leak-

6

free system at maximum vacuum of -6.0 mbar.

The conical seal (5) limits the vacuum

– Vacuum

when the diaphragm is raised.

– Atmosphere

Opens at -6.0 mbar, closes at -3.0 mbar.

– Pressure

2_448_11

36

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raised. It closes and opens at -2.5 mbar relative vacuum.

2012 911 Section 2-2 11/3/11 10:15 AM Page 37

911 Carrera 911 Carrera S

NVLD module (pneumatic part), operating principle under pressure

NVLD: Mechanical Function – At Rest

DME engine electronics

2

7 – Vacuum

No. 7 (see Fig. 2_449_11) shows the

– Atmosphere

NVLD module at ambient pressure. The

– Pressure

ventilated NVLD module and diaphragm

2_449_11

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(4) are in neutral position.

No. 8 (see Fig. 2_450_11) shows the

NVLD: Mechanical Function – Pressure at + 1.0 mbar

NVLD module at 1 mbar overpressure.

The diaphragm moves downward in the

8

event of overpressure and opens the

conical seal (5). Opening starts at +1.0 – Vacuum

mbar.

– Atmosphere – Pressure

2_450_11

No. 9 (see Fig. 2_451_11) shows the

NVLD: Mechanical Function – Pressure at + 5 mbar

NVLD module at +5 mbar (fully open at

9

maximum overpressure).

– Vacuum – Atmosphere

In other words, the pressure in the fuel

– Pressure

tank always moves between - 6.0 … +5.0 mbar in the stable condition.

2_451_11

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911 Carrera 911 Carrera S

DME engine electronics

2

Leak test The NVLD tank leakage diagnostic system is passive. It works by measuring the pressure difference between the warm and cold fuel tank. In order to reliably determine the absence of leaks in the system, the fuel tank must be left to cool down for an extended period of time (e.g. overnight). This means that it is not possible to check whether the tank system is leak-free by means of a quick test using on-board diagnosis after a repair.

Consequently, a smoke test is provided for performing a quick leak test of the tank system using NVLD in the workshop. The smoke test is described in the PIWIS

Note: On vehicles with NVLD, the DME actual value “E010” indicates whether the tank system was leak-free during the most recent long-term test in the stationary vehicle.

2_453_11

38

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information system.

2012 911 Section 2-2 11/3/11 10:15 AM Page 39

911 Carrera 911 Carrera S

2.9 Ignition system The components and functions of the ignition system such as • spark plugs • individual ignition coils with integral driver • 2 knock sensors

DME engine electronics

2

are the same as on the previous model.

The country-specific change intervals for the spark plugs, plug type, heat rating and tightening torques can be found in the PIWIS information system/maintenance

Differential Hall-effect sensor Similar to the Panamera and Cayenne with Auto Start Stop function, the differential Hall-effect system is used to determine the engine speed instead of the previous inductive pick-up. In addition to detecting the engine speed and reference mark, the new multiple Hall-effect sensor also detects the direction of rotation of the engine.

This function enables the engine to be started very quickly. The speed sensor, which is installed on the transmission bell housing, features three integrated Halleffect sensors (A - B - C). Only one rotor with 60 - 2 teeth is needed on the crankshaft to generate the corresponding PWM signal.

• Differential Hall-effect sensor for – detecting the engine speed, – reference mark and – direction of rotation of the engine

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schedule.

2_454_11

• 3 Hall senders in the sensor • 1 rotor on the crankshaft • PWM signal • Temperature-insensitive

2_455_11

• Suitable for high engine speeds

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911 Carrera 911 Carrera S

2

All exhaust system variants feature flow-optimized exhaust manifolds with catalytic converters arranged close to the engine (see Fig. 2_457_11, 1) as well as a common front muffler (see Fig. 2_456_11, 2) and one main muffler (3) per cylinder bank with corrugated tube (4).

2_457_11

2_456_11

The purpose of the corrugated tube on the main muffler is to improve vibration comfort during idling.

The specifications for the exhaust systems are described on the following pages.

The following are installed worldwide for all engines: 2_458_11

• Identical flow-optimized exhaust manifold/catalytic converter modules • 5 different front mufflers • 3 different main mufflers • 3 different tailpipe covers

!

Caution when handling: Do not pick up the main muffler by the short tube end!

Risk of deforming the corrugated tube (4).

40

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DME engine electronics

2.10 Exhaust system, emission control

2012 911 Section 2-2 11/3/11 10:15 AM Page 41

911 Carrera 911 Carrera S

Standard exhaust system for the 3.4-liter engine

2

The 3.4-liter engine features a twin-branch exhaust system with catalytic converters arranged close to the engine (1) on the flow-optimized exhaust manifold, a common

DME engine electronics

front muffler (2), two main mufflers (3) and individual tailpipe covers (4) as standard.

The main mufflers (3) have an intake pipe and exhaust pipe with a diameter of 55 mm.

The exhaust system has been derestricted by optimizing flow characteristics in order to reduce exhaust backpressure.

Twin-branch exhaust system

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2_461_11

1 Catalytic converters arranged close to the engine on the exhaust manifold 2 One common front muffler

3 One main muffler per cylinder bank 2_459_11

4 Individual tailpipe covers

2_460_11

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911 Carrera 911 Carrera S

DME engine electronics

2

Exhaust system for the 3.8-liter engine Layout of the 911 Carrera S flap exhaust system (standard on the S model) The 3.8-liter Carrera S engine features a four-branch exhaust system with catalytic converters arranged close to the engine (1) on the flow-optimized exhaust manifold, a common front mufflers (2), two flap-controlled bypass pipes (3), two main mufflers (4) and two twin tailpipe covers (5).

The main mufflers (4) have an intake pipe with a diameter of 55 mm and an exhaust

2_465_11

2_464_11

2_462_11

The map-controlled, electropneumatic flap control of the 911 Carrera S exhaust system increases the engine power by further reducing exhaust backpressure at increased rpm and engine load.

1 Catalytic converters arranged close to the engine on the exhaust manifold 2 Front muffler 3 With two exhaust flaps on the front muffler 4 One main muffler per cylinder bank 5 Twin tailpipe covers

2_463_11

42

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pipe with a diameter of 52 mm.

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911 Carrera 911 Carrera S

Exhaust flap switching (Carrera S) The Carrera S exhaust system does not feature a switch for activating and deactivating the exhaust flaps.

The exhaust flaps are activated using a map in the DME control unit as a function of

DME engine electronics

2

engine speed and load: • Engine speed: >3,300 rpm • Load: Slight, partial-load acceleration (corresponds to an air mass of 400 mg/stk)

In this case the DME control unit sends a CAN signal via the gateway to the rear-end

Sports exhaust system (available as an option for the 3.4-liter and 3.8-liter engines) A completely redesigned sports exhaust system is available for the 911 Carrera (991) models. The main innovation to the sports exhaust system is an extended functionality. For the first time, activating the sports exhaust system not only derestricts the exhaust gas routing but also enables the two exhaust tracts to be connected. This pairs an unmistakable flat-six engine sound with optimum performance. This results in more emotive acoustics.

For visual differentiation, the sports exhaust system has two twin tailpipes with a unique nozzle design and nano-coating.

Exhaust flap switching (sports exhaust system)

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electronics, which activate the electropneumatic switching valve.

2_466_11

On the optional sports exhaust system, switching of the exhaust flaps to an acoustically optimized mode can only be activated or deactivated following a request using one of the following buttons: • Sport button • Sport Plus button

2_467_11

• Sports exhaust system button (the sports exhaust system can also be deactivated using this button).

The exhaust flaps are activated in accordance with the request using the map in the DME control unit, as on the Carrera S.

In this case the DME control unit sends a CAN signal to the gateway; it receives the corresponding button request via CAN from the operating and air conditioning unit.

Only then does the gateway send a CAN signal to the rear-end electronics, which activate the electropneumatic switching valve.

2_468_11

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911 Carrera 911 Carrera S

DME engine electronics

2

Layout of the sports exhaust system (available as an option for the 3.4-liter and 3.8-liter engines) Four-branch sports exhaust system with catalytic converters arranged close to the engine on the flow-optimized exhaust manifold, a common front muffler (1) with central map-controlled, electropneumatically switchable exhaust flaps of the bypass pipes (3), two main mufflers (4) and two twin tailpipe covers (5) with unique nozzle design. The main mufflers (4) have an intake pipe with a diameter of 55 mm and, in

2_469_11

2_470_11 2_471_11

• Sporty sound and improved torque curve • Two twin tailpipes with a unique nozzle design • An acoustically optimized mode can

On the sports exhaust system, activating the exhaust flaps also reduces the exhaust back pressure (for a sporty sound and improved torque curve) as well as establishing a connection between banks 1 and 2. The connection results in resonance induction between the left and right cylinder banks.

be activated and deactivated by pressing a button • When the sports exhaust system is activated, the indicator light in the button lights up 1 Front muffler with 2 Connection as well as 3 Two central exhaust flaps with modified positioning 4 One 52 mm main muffler per cylinder bank (50 mm in some cases) 5 Two twin tailpipes with a unique nozzle design

44

2_472_11

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some countries, an exhaust pipe with a diameter of 52 mm or 50 mm.

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911 Carrera 911 Carrera S

Emission control, catalytic converter, oxygen sensors There is one three-way main catalytic converter with ceramic monolith (1) per cylinder bank installed at the end of the flow-optimized exhaust manifold. The catalytic converter diameter is 125 mm, the length 120 mm, it has 400 cells and a wall thickness of 4.5 mm.

DME engine electronics

2

The oxygen sensor LSF downstream of the catalytic converter (3) is installed seven tenths of the way along the length of the main catalytic converter; this corresponds to 84 mm from the intake surface.

The funnel (4) upstream and downstream of the catalytic converter is air-gap

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insulated to reduce the emission levels.

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Bank-specific oxygen sensor closed-loop control with: 1

Ceramic main catalytic converter (three-way), left + right

2

Broadband oxygen sensors (LSU) upstream of catalytic converter

3

Oxygen sensors (LSF) downstream of catalytic converter

4

Air-gap insulated funnel upstream and downstream of catalytic converter

The vehicles comply with the worldwide exhaust emission standards: EURO 4

(EOBD)

EURO 5

(EOBD)

USA LEV II

(OBD II)

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DME engine electronics

2

2.11 Auto Start Stop function General The Auto Start Stop function installed as standard on all vehicles (Porsche Doppelkupplung [PDK] and manual transmission) offers the following advantages: • Unnecessary engine idling, for example when stopped at a traffic light, is prevented • Fuel consumption and the corresponding emissions are reduced, particularly during city driving • The noise level of the engine is reduced to zero during the stop phase (radiator fans keep running) • The ignition remains switched on, even when the engine is automatically

• All functions keep working

Operating principle 2_476_11

All 911 Carrera models feature an Auto Start Stop function as standard. The starter is designed for the increased number of starting operations. This is the first time that Auto Start Stop has been available on the 911 Carrera models in conjunction with the 7-speed manual transmission. All the driver has to do is to disengage the gear and remove his/her foot from the clutch pedal when the vehicle is stationary, for example in a traffic jam or in stop-and-go traffic. All he/she needs to do to continue driving is engage the gear. The engine starts immediately after the clutch pedal is pressed.

The Auto Start Stop function switches off the combustion engine under defined conditions when the vehicle is stopped and therefore helps to reduce fuel consumption and increase comfort when the vehicle is stationary. It switches off the engine automatically, for example when waiting at traffic lights, when the vehicle has come to a stop and the brakes are on or, in the case of the manual transmission, when the selector lever is in the neutral gate and the clutch pedal is not pressed. The tachometer falls to zero and the driver is informed of activation of the Auto Start Stop function by a symbol in the display of the instrument cluster. The audio and communication systems remain switched on despite the engine being switched off and the climate control also maintains the selected temperature level.

The criteria have been optimized and fine-tuned in order to ensure that the engine is switched off automatically in as many cases as possible during regular driving operation in order to exploit the fuel-saving potential of the Auto Start Stop function for the driver.

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switched off

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911 Carrera 911 Carrera S

Display for the Auto Start Stop function The Auto Start Stop function can be automatically switched on or off by way of country-specific coding.

1

When the function is switched off, the “A” symbol in the button lights up red.

2

When the engine is automatically switched off, the “A” Auto Start Stop

DME engine electronics

2

symbol in the instrument cluster lights up green.

3

If the engine cannot be switched off automatically, the “A” Auto Start Stop symbol in the instrument cluster lights up amber.

Manual engine start after leaving the vehicle The message “Please start engine manually” appears in the instrument panel

• the driver’s door was opened.

Activation/deactivation The Auto Start Stop function can be deactivated and activated by means of a button in the center console. The function becomes available as soon as the engine and transmission reach operating temperature. In conjunction with the Porsche Doppelkupplung (PDK), the operating principle of the Auto Start Stop function is comparable with the Cayenne and Panamera models.

Auto Start Stop function and coasting mode Deactivating

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• if, for example, the driver’s seat belt was released or

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• Press the button.

• The indicator light in the button comes on.

• Automatic stopping of the engine is suppressed and coasting mode is deactivated.

Activating

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• Press the button.

• The indicator light in the button goes off.

• The engine is automatically switched off when the vehicle stops and coasting mode is activated.

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DME engine electronics

2

Restart readiness If the engine cannot be automatically stopped or if no driver is detected in the vehicle (driver’s seat belt released or driver’s door open) after the automatic engine stop, the indicator light in the multi-function display on the instrument panel lights up amber in the stationary vehicle.

The Auto Start Stop system has detected that: • At least one prerequisite for the automatic engine stop is not met or • at least one exemption condition of the Auto Start Stop function is present.

• Auto Start Stop function switched on • Engine cover closed • Driver detected: driver’s seat belt fastened and driver’s door closed • PDK selector lever in position D, N or P or transmission range 1 or 2 selected manually or in the case of the manual transmission in neutral position and clutch pedal not depressed • Engine, transmission and battery have reached operating temperature • The vehicle has been driven at more than 1.2 mph (2 km/h) for at least 1.5 seconds since the last automatic engine stop

Engine stop If the vehicle is stopped by pressing the brakes and the brake pedal is held, the Auto Start Stop function switches off the engine after approx. 1 second. The green Auto Start Stop symbol in the instrument cluster informs the driver of this. The rev counter falls to zero. With PDK the selector lever can remain in position D or M. The engine remains stopped even if the lever is shifted to P and N.

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Prerequisites for the automatic engine stop

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911 Carrera 911 Carrera S

Vehicles with Porsche Doppelkupplung (PDK): 1. Brake vehicle to a stop with the footbrake 2. Keep footbrake depressed or select PDK selector lever position P

DME engine electronics

Vehicles with manual transmission:

2

1. Brake vehicle to a stop with the footbrake 2. The engine will stop if the gear lever is in neutral and the clutch pedal is no longer depressed

Engine start The Auto Start Stop function starts the engine: Vehicles with Porsche Doppelkupplung (PDK):

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PDK selector lever in position D or N or transmission range 1 or 2 selected manually – release footbrake. or – press accelerator pedal.

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or – select PDK selector lever position R.

Vehicles with manual transmission: Press clutch pedal down fully and engage gear from neutral.

It is possible to drive off as normal.

Manual engine start after leaving the vehicle

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The engine will not be automatically started if the driver’s seat belt is released or the driver’s door is opened after an automatic engine stop.

If the brake is also released, the engine must be started manually.

The message “Please start engine manually” appears in the multi-function display on the instrument panel.

2_479_11

!

The engine is automatically started independently in certain situations (e.g. when the vehicle is rolling) to maintain the airconditioning comfort or if the brake vacuum is falling.

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DME engine electronics

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Exceptions The Auto Start Stop function is not available in the following situations, for example: • When Sport mode is activated.

• When PSM is switched off.

• During manoeuvring.

• When AC MAX mode is activated.

• When the “Windshield defrost” function is active.

• At elevations above approx. 9850 ft (3,000 meters).

• After engaging a gear without pressing the clutch pedal when the

!

Diagnostic options for the Auto Start Stop function using the PIWIS Tester, for

The Auto Start Stop function is available with limited functionality in the following situations, for example: • If the air conditioning or passenger compartment heating is operated at a high setting or if the defrost function is running for long periods of time.

example:

• If the charge state of the battery is low.

• DME actual values: ST010 to ST320

• On uphill or downhill gradients.

• Drive links

• When vehicle-internal test processes are taking place, for example automatic

• Guided Fault Finding

engine diagnosis.

• In the case of excessively low exterior or battery temperature.

Information: Automatic engine restart is possible if one of these states occurs after the engine has been switched off automatically.

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engine is automatically stopped.

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911 Carrera 911 Carrera S

2.12 Coasting function The 911 Carrera models now feature the coasting function in conjunction with the Porsche Doppelkupplung (PDK). Coasting refers to operating the vehicle with the

DME engine electronics

engine disengaged, for example on slight downhill gradients; the engine is operated at idle speed so that the function of the auxiliary systems (alternator, air-conditio-

2

ning compressor, coolant pump, etc.) is maintained.

During coasting, the kinetic and potential energy of the vehicle is directly used to overcome driving resistance. Although no fuel is used during deceleration with deceleration fuel cutoff, the vehicle is significantly decelerated. If no deceleration is

Activating and deactivating coasting mode Coasting mode is activated and deactivated using the Auto Start Stop button.

Deactivating:

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• Press button (1) • The indicator light in the button lights up red • Coasting mode is deactivated and automatic stopping of the engine is suppressed

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desired, additional fuel must be used to cover the lost distance.

1 The Auto Start Stop button switches the Auto Start Stop function on and off and activates and deactivates

Activating: • Press button (1) • The indicator light in the button goes off • Coasting mode is activated and the engine is automatically switched off when the vehicle stops

coasting mode.

Prerequisites for coasting mode: • Driving in selector lever position D • Coasting mode is activated (indicator light in the button is off) • Sport or Sport Plus mode is deactivated • PSM is active • Control cruise mode is not active • Engine, transmission and battery have reached operating temperature • Relaxed/economic driving style • Only a slight uphill or downhill gradient • Remove foot slowly from accelerator pedal The engine is disengaged and runs at idle speed. The vehicle rolls with no engine braking effect. Coasting mode can be identified by the tachometer showing idle speed.

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DME engine electronics

2

Deactivation of the coasting function Automatically With a sporty driving style or if the accelerator pedal is released suddenly, coasting mode is suppressed to allow targeted use of the engine braking effect. Likewise, coasting does not occur on steep uphill gradients since the coasting phase would be very short due to the uphill gradient and no significant fuel saving is possible.

Coasting mode is suppressed on steep downhill gradients since the vehicle does not slow down, despite the engine deceleration torque, and the use of deceleration fuel cutoff means that no fuel is consumed in this driving situation.

Manually

• Press the brake pedal or • Press a shifting paddle or a shift button or • Change gears using the selector lever

Activation of the coasting function If coasting mode is suppressed, for example due to a sporty driving style, sudden release of the accelerator pedal or excessively low engine temperature, it can be initiated manually by shifting up a gear with the shift paddle, one of the shift buttons or the selector lever.

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• Press the accelerator pedal or

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911 Carrera 911 Carrera S

2.13 Thermal energy management DME engine electronics

2

The new 911 Carrera (991) features a comprehensive thermal management system for the first time. The advantages achieved compared with the previous model are as significant as the possible operating states of the thermal management system are varied. Thermal management not only involves the engine, but also the transmission and heating.

Objective Networking of all relevant heat sources in order to • Reduce consumption by controlling the heat flows during all phases (up to 2%) • Reduce emission values • Reduce internal friction in the engine and transmission

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2_480_11

• Increase performance • Improve aerodynamics by doing away with air intakes in the underbody panelling, this also increases the top speed up to 189 mph (304 km/h) • Increase heating comfort • Enhance the OBD functions

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DME engine electronics

2

Coolant temperature level, engine Warm-up

At operating temperature

Cooling

221° F.

Coolant temperature approx.

185° F.

Time Picture above: Comparison of coolant temperature level between Carrera 991 (S) and 997 (2)

991 (S)

Warm-up Fig. 2_482_11 coolant temperature to 185° F. (85° C.) during periods of increased operating load, or by actuating a map-controlled thermostat when Sport/Sport Plus mode is activated.

At operating temperature

Cooling

Consumption 221° F. 185° F. Coolant temperature approx.

Performance enhanced by reducing the

997 (2)

Performance

Time 2_482_11

The speed with which the operating temperature is reached is achieved by way of an innovative rotating piston valve that is actuated by the DME control unit according to a control map. The engine is at operating temperature when an engine coolant temperature of 221° F. (105° C.) is reached.

Operating modes The operating modes of the thermal management system can be categorized as follows for the 991: 1. Operating mode: Warm-up a) Measures aimed at reducing fuel consumption • Specific channelling of available heat flows to operating fluids and components that are relevant to consumption • Reduces heat losses to a minimum, accelerates warm-up

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2_481_11

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911 Carrera 911 Carrera S

b) Increased heating comfort Specific channelling of the available heat flows into the passenger cell 2. Operating mode: At operating temperature

DME engine electronics

• Reduces consumption by increasing the coolant temperature (221° F./ 105° C.) 3. Operating mode: Cooling

2

!

• Optimizes performance by reducing the coolant temperature (185° F./85° C.)

Note: The coolant temperature gauge in the

• Reduces the cooling of operating fluids and components relevant to

instrument cluster shows 194° F. (90° C) at

consumption after the engine is switched off until it is started again

normal operating temperatures 185° F. -

Overview of the engine cooling system from the front

221° F. (85° C. - 105° C.).

11 Connection for heat exchanger and expansion tank

1 10 9 2

2

Coolant return line for coolant radiator

3

Map-controlled thermostat

4

Mechanical coolant pump

5

Coolant return line forcylinder banks 1 and 2

8 6

5

Coolant supply line for cylinder banks 1 and 2

7

7

Coolant shut-off valve (electropneumatically actuated)

8

Coolant supply line for coolant radiator

9

Coolant return line for

4

engine oil heat exchanger

6

10

3

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1

Coolant supply line for engine oil heat exchanger

11

Engine vent line

2_483_11

Shut-off valves The coolant throughput to different components is controlled in the cooling system of the 991 (S) by way of the map-controlled thermostats (3) on the one hand and electropneumatically actuated valves (7) on the other.

Electropneumatic switching valves The thermal management system features electropneumatic shut-off valves for the following components: • Engine coolant shut-off valve (7) 2_484_11

• Heat exchanger • Gear oil heat exchanger

Electropneumatic disc valve

• ATF heat exchanger (Porsche Doppelkupplung [PDK] only)

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2

DME engine electronics

Vacuum system The 991 has a maximum of eight electropneumatic valves in total, four of which belong to the thermal management system. Further electropneumatic valves are used to switch • the tuning flap (991 S only), • the air cleaner flap, • the sound symposer and

* 991 S only

• the sports exhaust system flap (optional).

** Only with the sports exhaust system (optional)

Overview of the vacuum system

*** Only with the Porsche Doppelkupplung (PDK) (optional)

Unfiltered air hose

See blue arrow

Mechanical vacuum pump

Valve for air cleaner box flap

2_487_11

Engine coolant shut-off valve

Vacuum hose

Valve for tuning flap*

Shut-off valve for heat exchanger

Valve for sound symposer

Shut-off valve for gear wheel heat exchanger

Direction of travel

1 Solenoid valve for shut-off valve for

Valve for exhaust flaps**

Shut-off valve for ATF heat exchanger*** 2_485_11

Vacuum lines, installation position on cylinder bank 2

heat exchanger 2 Shut-off valve for heat exchanger (pneumatic) 3 Unfiltered air connection, solenoid valve for exhaust flaps (exhaust flaps only with sports exhaust system, optional) 4 Solenoid valve for engine coolant shutoff valve 5 Solenoid valve for tuning flap switching valve (991 S only) 6 Switching valve for tuning flap (pneumatic, 991 S only) 7 Vacuum connecting line for transmission

Vacuum Unfiltered air Control line

56

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Air cleaner housing

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911 Carrera 911 Carrera S

Vacuum lines, installation position on air cleaner box/cylinder bank 2

DME engine electronics

2

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See blue arrow

2_487_11

The solenoid valves for the sound symposer switching valve and for the air cleaner

1 Solenoid valve for sound symposer

flap are installed on the right behind the air cleaner box.

switching valve

2 Solenoid valve for air cleaner flap

Diagnosing faults in the vacuum system

switching valve

3 Solenoid valve for heat exchanger shut-off valve

Vacuum Unfiltered air Control line 1 Switching valve for exhaust flaps (pneumatic, sports exhaust system [optional] only) 2_490_11

2 Map-controlled thermostat 3 Switching valve for engine coolant shut-off valve

Diagnosing faults in the vacuum system The electric solenoid valves in the vacuum system are fully diagnosable (short circuit/open circuit); electrical faults result in an entry in the DME control unit and, if applicable, in the PDK control unit.

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2

switching valves and the associated effects. The DME control unit cannot, however, output an unequivocal fault message in the event of leaks in the vacuum system because there are too many different vacuum components connected. For example, a leak in the pneumatic switching valve for the tuning flap could generate a fault message about the cooling system.

!

It is important to proceed as per the

Background knowledge on electropneumatically controlled valves

specifications of the Workshop

The pneumatic valves are switched in steps, in other words they are either fully

Manual/Guided Fault Finding when

closed or fully open. They can, in principle, also be operated continuously, but the

troubleshooting the vacuum system.

compression properties of air mean that this cannot be done with any precision.

Background knowledge on electronically controlled actuators Consequently, electrical actuators are currently used for precise, continuous control of valves; these have the following disadvantages compared with pneumatic valves: • Higher production costs • Higher weight • More complicated activation A further advantage of the electrically actuated valves is their better diagnostic capabilities. Feedback devices (potentiometers) are attached to the drive links and communicate the position detected by the actuator directly to the control unit, which also makes for easy and precise control of the relevant component.

Engine coolant shut-off valve The engine coolant shut-off valve (electropneumatically actuated) is designed as a rotating piston valve and is used, among other things, to reach the engine operating temperature faster during the warm-up phase. The coolant throughput is increased as required by closing the electropneumatically actuated coolant shut-off valve via the DME control unit.

Closing the engine coolant shut-off valve (vacuum present) largely prevents the coolant circulating in the engine, even though the impeller of the mechanically driven coolant pump is turning. This applies as long as the map-controlled 2_500_11

thermostat is closed.

The coolant in the engine means that the combustion engine reaches its operating temperature much faster than in systems without thermal management, however the coolant pressure also increases along with the engine speed. If the engine coolant shut-off valve is closed when the thermostat is open, the coolant throughput in the coolant radiators increases. The engine coolant shut-off valve must be open above 3,000 rpm as high pressures would otherwise build up in the cooling system, possibly resulting in leaks and damage to the cooling system.

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DME engine electronics

Leaks in the vacuum system are detected through the malfunctioning of pneumatic

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911 Carrera 911 Carrera S

The engine coolant shut-off valve is closed as a function of: • Setpoint engine coolant temperature • Engine coolant temperature

DME engine electronics

• Coolant temperature at the radiator outlet • Gear oil and ATF temperature (Porsche Doppelkupplung [PDK] only)

2

• Heating request to the air conditioning system • Engine power • Engine speed • Ambient air temperature

The engine coolant shut-off valve is kept closed in the following operating modes by

• Heating phase (not USA) • Maximum cooling

2_501_11

• Heating engine boost mode

Diagnosis

Component

Condition Stuck open • No electrical connection • No pneumatic connection • Valve sticking

Engine coolant shut-off valve

Stuck close • Short circuit to ground • Activation lines • interchanged • Valve sticking

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the DME control unit:

Consequence • • • •

Extended heating phase Increased fuel consumption Restricted cooling performance

• • • • •

Overheating in the cylinder head Pressure in the cooling system too high (leaks in the cooling system)

The evaluation electronics can detect mechanical faults in the map-controlled thermostat and engine coolant shut-off valve by evaluating the temperature signals, but cannot identify which of the specified components is defective. A thermostat or engine coolant shut-off valve that is stuck closed will result in an entry in the fault memory after a diagnostic routine.

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DME engine electronics

2

Thermal management for heat exchanger Coolant flows through it during: • Heating requests • Maximum engine cooling requests

2_503_11

2_502_11

The shut-off valve for the heat exchanger is opened via the air conditioner control unit when the driver requests heat. The engine coolant shut-off valve, which is closed when the engine is not yet at operating temperature, ensures that sufficient hot coolant is available even after a very short time in order to heat the passenger compartment.

When the passenger compartment no longer needs to be heated, the shut-off valve for the heat exchanger is closed again so that the combustion engine can reach its operating temperature faster.

The shut-off valve for the heat exchanger is also automatically opened when a request for maximum engine cooling is sent via a CAN message from the DME control unit to the air conditioner control unit in order to further reduce the coolant temperature in the engine and in this way prevent damage to the engine and transmission.

Closing the engine coolant shut-off valve below 1,800 rpm increases the flow of coolant in the heat exchanger, but also increases the heating output considerably (heating boost mode).

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Shut-off valve for heat exchanger

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911 Carrera 911 Carrera S

Diagnosis

Shut-off valve for heat exchanger

Condition

Consequence

Stuck open • No electrical connection • No pneumatic connection • Valve sticking

• Extended heating phase • Increased fuel consumption

Stuck closed • Short circuit to ground • Activation lines • interchanged • Valve sticking

• No heating of the passenger

2

DME engine electronics

1

Thermal management for gear wheel set (Porsche Doppelkupplung [PDK] and manual transmission) Gear oil heating A temperature sensor (see photo on the next page) is installed close to the gear oil

2_504_11

heat exchanger (which is attached to the transmission housing) that continuously detects the gear oil temperature and communicates this information to the DME control unit.

To heat up the gear oil faster, the shut-off valve for the gear oil heat exchanger (1) is opened during the engine warm-up phase as soon as the coolant has reached a temperature of 158° F. (70° C.) and is therefore hotter than the gear oil. The coolant then flowing into the gear oil heat exchanger (2) boosts heating of the gear oil to the setpoint temperature of 194° F. (90° C.). The friction in the gear wheel set

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Component

2

2_505_11

is reduced faster (the viscosity characteristics of the oil improve when the oil temperature increases), shifting comfort is increased and fuel consumption is reduced.

1 Pneumatically actuated shut-off valve The shut-off valve is closed (vacuum present) as soon as the setpoint gear oil temperature of 194° F. (90° C.) is reached. This prevents excessive heating of the gear

for gear oil heat exchanger 2 Gear oil heat exchanger

oil.

The specified temperatures are for guidance only and may vary depending on the operating condition and variant.

Gear wheel cooling The disc valve is opened again if the gear oil temperature increases beyond the setpoint temperature and beyond the temperature of the coolant; the purpose of this is to cool the gear oil (component protection).

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DME engine electronics

2

Gear oil pump The cooling oil is supplied to the gear wheel set via a Wankel pump (1) installed directly at the heat exchanger (see Fig. 2_506_11, 2) and driven by a pinion shaft.

This way that the supply of cooling oil to the gear wheel set is speed-dependent.

1

1 Gear oil pump (installation position) 2 Gear oil heat exchanger 3 Gear oil temperature sensor (NTC)

3

Direction of travel 2_506_11

Diagnosis

Component

Shut-off valve for gear oil heat exchanger

Fault

Consequence

Stuck open • No electrical connection • No pneumatic connection • Valve sticking

• Extended heating phase • Increased fuel consumption • Increased wear on the • transmission possible • during normal driving at 2221° F. (105 °C.)

Stuck closed • Short circuit to ground • Activation lines • interchanged • Valve sticking

• Overheating of the transmission possible (at high engine speeds and loads, high ambient temperatures)

2_507_11

Thermal management for the Porsche Doppelkupplung (PDK) The Porsche Doppelkupplung (PDK) in the 991 features an additional ATF heat exchanger (1 on the following page) that is integrated in the thermal management system for the entire vehicle by way of sensors. The ATF temperature sensor (on the right in the picture) is necessary for this. The DME control unit receives its values via the PDK control unit. The ATF heat exchanger (1 on the following page) is mounted on the PDK housing. Its purpose is to heat the ATF faster (and cool it if necessary) or to cool the oil-cooled and oil-lubricated double-clutch transmission.

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2

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911 Carrera 911 Carrera S

2

DME engine electronics

2

1 ATF heat exchanger 2 Solenoid valve for ATF heat exchanger 3 Pneumatic shut-off valve for ATF heat exchanger

3

2_508_11

ATF heating To heat up the ATF faster, the shut-off valve for the ATF heat exchanger (3) is opened during the engine warm-up phase as soon as the coolant has reached a temperature of 158° F. (70° C.) and is therefore hotter than the ATF. The coolant then flowing into the ATF heat exchanger (1) boosts the heating of the ATF to the setpoint temperature of 185° F. (85° C.). The friction losses of the moving parts in the hydraulic area of the transmission are reduced (the viscosity characteristics of the oil improve when the oil temperature increases), shifting comfort is increased and fuel consumption is reduced.

Installation position

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1

2_509_11

If the setpoint ATF temperature of 185° F. (85° C.) is reached, the DME control unit actuates the solenoid valve for the ATF heat exchanger (2) and the solenoid valve directs vacuum to the pneumatic shut-off valve (3). The shut-off valve closes and prevents any more coolant flowing into the heat exchanger. This prevents excessive heating of the ATF.

The specified temperatures are for guidance only and may vary depending on the operating condition.

ATF cooling Operation of the double-clutch transmission results in greater heating of the ATF than of the gear oil. The disc valve is opened again if the ATF temperature increases beyond the setpoint temperature and the engine coolant temperature is below the temperature of the gear oil. The coolant circulating in the ATF heat exchanger cools the gear oil (component protection).

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DME engine electronics

2

Component protection for the Porsche Doppelkupplung (PDK) A message appears in the instrument cluster (first white, then red transmission temperature warning) as a safety measure if the transmission overheats. The DME control unit additionally reduces the torque until the ATF temperature reaches a non-critical value again. The warning message then disappears.

Component

Shut-off valve for ATF heat exchanger

Condition

Consequence

Stuck open • No electrical connection • No pneumatic connection • Valve sticking

• Extended heating phase • Increased fuel consumption • Close to the critical clutch temperature

Stuck closed • Short circuit to ground • Activation lines • interchanged • Valve sticking

• Overheating of the transmission/clutch possible (lots of gear changes, racing starts, high ambient temperatures are critical)

Map-controlled thermostat The map-controlled thermostat is an insertion map-controlled thermostat with a heating element. The map-controlled thermostat can be energised via the DME control unit. The flow of current through the heating element (electric resistor) causes it to heat up, which in turn influences the expansion element in the thermostat and enables it to be opened. Actuation by the DME control unit is 2_510_11

performed by means of pulse width modulation, which means that the coolant temperature level can be continuously controlled.

Thermostat (997 II)

+

Heating element The usual coolant temperature when the engine of the 991 (S) is at operating temperature is 221° F. (105° C); it is reduced to 185° F. (85° C.) during sporty driving and in Sport/Sport Plus mode by opening (energising) the thermostat. This supports a performance-oriented driving style.

The DME control unit can also have the thermostat closed by switching off the heating current. The coolant temperature must be less than 216° F. (102° C.) for this to be possible. The map-controlled thermostat starts to open at 216° F. (102° 2_511_11

=

Map-controlled thermostat (991)

64

C.) +/- 36° F. (2° C.) when de-energized and is fully open at 239° F. (115° C.).

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Diagnosis

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911 Carrera 911 Carrera S

The coolant temperature is measured by the engine coolant temperature sensor and the radiator outlet coolant temperature sensor and transmitted to the DME control unit.

DME engine electronics

The DME control unit energizes the heating element (resistor) in the map-controlled

2

thermostat: • In the lower and medium load range in order to limit the coolant temperature in the engine to 221° F. (105 C.).

• With an increased load requirement as well as during operation in Sport and Sport Plus mode in order to reduce the engine coolant temperature to 185° F. (85° C.). The cooler cylinder walls result in higher density of the

the performance of the combustion engine.

• If necessary to prevent critical gear wheel oil and ATF (Porsche Doppelkupplung [PDK] only) temperatures. The heat exchanger can also be activated for this purpose.

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oxygen content in the combustion chamber. The improved charging enhances

2_512_11

Diagnosis The map-controlled thermostat is diagnosable for legal reasons. Electrical faults and detection of a thermostat that is stuck open result in an entry in the fault memory, the OBD indicator light comes on and the warning message “Cooling system error” appears in the instrument cluster.

A thermostat or an engine coolant shut-off valve that is stuck closed is also indicated in the instrument cluster by way of the warning message “Cooling system error”, but the OBD indicator light does not come on. The evaluation electronics cannot yet correctly identify whether the map-controlled thermostat or the coolant shut-off valve is defective. As of MY 12/13 it will be possible to correctly identify which of the specified components is defective with the help of PIWIS Tester II using the “Short test” function.

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DME engine electronics

2

Component

Fault

Consequence

Stuck open

• Extended heating phase • Increased fuel consumption

Stuck closed

• Overheating of the cooling system

Map-controlled thermostat

The following parameters are used for diagnosis: • Setpoint engine coolant temperature • Engine coolant temperature • Coolant temperature at the radiator outlet

• Mass air flow • Deceleration phases • Vehicle speed • Ambient temperature

Engine coolant temperature sensor The engine coolant temperature sensor (NTC) is installed in cylinder bank 1 near the third cylinder and is designed as a temperature-dependent resistor.

2_514_11

2_513_11

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• Engine speed

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The sensor signal is used for: • DME control (ignition/injection system) • Actuating the engine coolant shut-off valve • Actuating the map-controlled thermostat • Actuating the engine compartment purge fan

DME engine electronics

2

• Checking the oil temperature sensor/oil temperature • Air conditioning control • Diagnosing the engine coolant shut-off valve • Cross-check diagnosis

Diagnosing the engine coolant temperature sensor (cross-check diagnosis)

working correctly. The control unit compares the temperature values of different sensors and checks them for plausibility.

The following temperatures are compared when checking the engine coolant temperature sensor: • Engine coolant temperature • Engine oil temperature • Intake air temperature • Ambient temperature

Step 1 When an engine is started after the ignition has been off for more than 8 hours, the specified temperature values are compared. The temperature values must not deviate by more than a certain value (depending on when the ignition was switched off). A suspected fault is set if the deviation is too great, but this must be confirmed

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The purpose of cross-check diagnosis is to check that temperature sensors are

in Step 2.

Step 2 The check is repeated if a journey during which the vehicle travels at more than 16 mph (25 km/h) for a total of 45 seconds takes place within 6 minutes of the engine starting. The relevant fault is written to the fault memory if the temperature of the suspected sensor continues to deviate by too much (difference > 77° F. (25° C.).

The suspected fault is dismissed and no fault is entered in the fault memory if the deviation in temperature of the suspected sensor is no longer as great. The suspected fault is dismissed and no fault is stored in the fault memory if the vehicle is not driven within 6 minutes of starting the engine.

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DME engine electronics

2

The following fault causes can be detected with the help of the engine coolant temperature sensor: • Engine coolant temperature sensor faulty • Thermostat/thermostat housing seal/thermostat housing faulty • Air in the cooling system • Oil temperature sensor faulty • Fault in DME

Radiator outlet coolant temperature sensor The radiator outlet coolant temperature sensor is located on the coolant pipe at the radiator outlet towards the engine on the vehicle underbody. The temperature

plausible signal to control the thermal management system.

The sensor signal is used for: • Actuating the coolant radiator fan – as a function of the coolant temperature 2_515_11

– as a function of the setpoint engine coolant temperature • Testing the function of the map-controlled thermostat/engine coolant shut-off valve • Diagnosis

Diagnosis The DME control unit compares the following values when checking the radiator outlet coolant temperature sensor:

!

Unapproved wheel retrofits (wheel

• Engine coolant temperature • Intake air temperature sensor The radiator outlet coolant temperature sensor can detect the following faults:

diameter too large) can result in a

• Radiator outlet coolant temperature sensor faulty

reduced air-flow rate at the coolant

• Engine coolant temperature sensor faulty

radiators.

• Engine coolant shut-off valve jammed • Radiator air intake covered with debris • Intake air temperature sensor faulty

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information is transmitted to the DME control unit. The DME control unit uses the

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911 Carrera 911 Carrera S

Operating modes The thermal management system is influenced by a number of different operating conditions. For that reason, only the most significant conditions are described here.

DME engine electronics

We will start with a few generally valid statements regarding the cooling system in the 991:

2

• The coolant cooling system for the engine is designed in two parts. The two parts are kept separate by the closed engine coolant shut-off valve.

• Coolant is continuously passed through the engine oil heat exchanger while the engine is running.

• As well as its primary task of cooling the engine, the cooling system is also used to heat/cool transmission oils. An ATF heat exchanger (Porsche Doppel-

purpose.

• Only vehicles intended for extremely hot countries have an additional center radiator. (Not for USA) • All solenoid valves are open when de-energized, i.e. all pneumatic valves are pressurized and therefore open.

1 Side radiator

First operating condition: Engine cold/off

2 Center radiator, variants for

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kupplung [PDK] only) and gear oil heat exchanger are integrated for this

extremely hot countries only (Not for USA) 3 Heat exchanger 4 Disc valve, vacuum-controlled 5 Comfort valve 6 Coolant expansion tank 7 Engine oil heat exchanger

8 ATF heat exchanger (Porsche Doppelkupplung [PDK] only) 9 Gear oil heat exchanger 10 Engine coolant shut-off valve 11 Map-controlled thermostat 2_516_11

12 Coolant pump (mechanical) 13 Engine coolant temperature sensor

Second operating condition: Heating boost mode • Ambient temperature < 32° F. (0° C.)

14 Coolant temperature sensor, radiator outlet

• Coolant temperature < 203° F. (95° C.) • Heating request present • n < 2,000 rpm • Coolant pressure < 14.5 psi (1 bar)

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2 2_517_11

The heating boost mode function enables faster heating of the passenger compartment. The heating boost mode function also has the task of preventing the passenger compartment from cooling down, even with low load requirements and very low outside temperatures.

In addition to the thermostat, the engine coolant shut-off valve (10) also stays closed up to an engine speed between 1,600 and 2,000 rpm when the ambient temperature < 32° F. (0° C.), coolant temperature < 203° F. (95° C.) and a maximum heating request is present. The closed engine coolant shut-off valve increases the coolant throughput in the heat exchanger (3) by approx. 60% compared with operation with the engine coolant shut-off valve open. The engine coolant shut-off valve is opened once the coolant temperature rises above 203° F. (95° C.).

Coasting mode (Porsche Doppelkupplung [PDK] only) is an exception. Heating boost mode remains active during coasting when outside temperatures are below 32° F. (0° C.) and a maximum heating request is present.

!

The procedure for filling and bleeding the

The map-controlled thermostat (11) is closed so that the coolant volume to be heated can reach its temperature faster.

cooling system must be followed as outlined in the Workshop Manual to

Comfort valve closed

prevent damage to the engine and

No coolant flows into the expansion tank (6) because the comfort valve (5) only

transmission.

opens the return lines from the two coolant radiators and engine to the expansion tank when the coolant pressure exceeds approx. 14.5 psi (1 bar). The closed comfort valve (5) ensures that there is less coolant to be heated at pressures below 14.5 psi (1 bar), which means that the coolant temperature can increase faster.

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DME engine electronics

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Any air bubbles in the cooling system cannot be automatically bled because the comfort valve does not open. During a pressure increase with air inclusions in the cooling system, the trapped air is compressed but the comfort valve remains

DME engine electronics

closed. This can result in overheating damage to the engine and transmission.

2

Third operating condition: Cold start/warm-up • Ambient temperature 59° F. - 95° F. (15° C. - 35 °C.) • Coolant temperature < 122° F. (50° C.) • Heating request • n <= 3,000 rpm

1 Side radiator 2 Center radiator, variants for

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• Coolant pressure > 14.5 psi (1 bar)

extremely hot countries only (Not for USA) 3 Heat exchanger 4 Disc valve, vacuum-controlled 5 Comfort valve 6 Coolant expansion tank 7 Engine oil heat exchanger

8 ATF heat exchanger (Porsche Doppelkupplung [PDK] only) 9 Gear oil heat exchanger 10 Engine coolant shut-off valve 2_518_11

11 Map-controlled thermostat 12 Coolant pump (mechanical)

13 Engine coolant temperature sensor Coolant throughput only takes place between the engine, engine oil heat exchanger (7) and, in the event of a heating request, the heat exchanger (3) so that the

14 Coolant temperature sensor, radiator outlet

temperature losses of the coolant are very low and the coolant heats up very quickly in the engine. The disc valve (4) of the heat exchanger (3) is opened in the event of a heating request so that coolant can flow into the heat exchanger.

Engine coolant shut-off valve control When the starting temperature (ambient temperature) is between 59° F. - 95° F. (15° C. - 35 °C.), the engine coolant shut-off valve (10) remains closed until the coolant in the engine has reached a temperature of 122° F. (50° C.) in order to heat the engine faster. The engine coolant shut-off valve (10) remains open if the ambient temperature exceeds 95° F. (35° C.).

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DME engine electronics

2

The engine coolant shut-off valve opens when an engine speed of 3,000 rpm is exceeded in order to prevent excessively high pressures in the cooling system. The map-controlled thermostat (11) is always closed during the heating phase.

Comfort valve open The slight increase in the coolant temperature causes the coolant pressure to exceed 1 bar and the spring-loaded comfort valve (5) to open. The return lines to the expansion tank are now opened and approx. 1.3 gal. (5 liters) of additional coolant are introduced into the cooling system.

Fourth operating condition: Warm-up • Ambient temperature >= 32° F. (0° C.)

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• Coolant temperature > 122° F. (50° C.) • Heating request

2_519_11

The engine coolant shut-off valve (10) remains open even at engine speeds below 3,000 rpm, regardless of whether or not a heating request is present, because the ambient temperature is high enough to heat the passenger compartment with the available coolant throughput and the available coolant temperatures.

The coolant in the small cooling system continues to heat up very quickly due to the still-closed thermostat (11) and the closed shut-off valves for gear oil cooling (9) and ATF cooling (8, Porsche Doppelkupplung [PDK] only). The shut-off valves for the gear oil heat exchanger and ATF heat exchanger can open from a minimum coolant temperature of 113 - 194° F. (45 - 90° C.), depending on the variant and operating condition.

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Fifth operating condition: Transmission heating • Coolant temperature > 113° F. (45° C.) < 194° F. (90° C.) • Gear wheel oil temperature < 194° F. (90° C.)

DME engine electronics

• ATF temperature < 185° F. (85° C.) (Porsche Doppelkupplung [PDK] only)

2

1 Side radiator 2 Center radiator, variants for extremely hot countries only (Not for USA) 3 Heat exchanger 4 Disc valve, vacuum-controlled 6 Coolant expansion tank 7 Engine oil heat exchanger

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5 Comfort valve

8 ATF heat exchanger (Porsche Doppelkupplung [PDK] only) 9 Gear oil heat exchanger 2_520_11

10 Engine coolant shut-off valve 11 Map-controlled thermostat

The shut-off valves for the gear oil heat exchanger (9) and ATF heat exchanger (8,

12 Coolant pump (mechanical)

Porsche Doppelkupplung [PDK] only) are opened within a coolant temperature range

13 Engine coolant temperature sensor

between 113° F. (45° C.) and 194° F. (90° C.). When the shut-off valves open

14 Coolant temperature sensor,

depends on the operating condition/variant. The coolant boosts the heating of the gear oil and ATF (Porsche Doppelkupplung [PDK] only) in this condition.

The shut-off valve for the gear oil heat exchanger (4) is closed once the setpoint

radiator outlet

gear oil of 194° F. (90° C.) is reached in order to prevent overheating of the gear oil. The shut-off valve for the gear oil heat exchanger (4) is opened again if the gear oil temperature falls below 158° F. (70° C.) in order to heat the gear oil again. This can occur especially during trips at very low ambient temperatures.

Porsche Doppelkupplung (PDK) only: The shut-off valve for the ATF heat exchanger is closed once the setpoint gear oil of 185° F. (85° C.) is reached in order to prevent overheating of the ATF. The shut-off valve for the ATF heat exchanger is opened again if the ATF temperature falls below 158° F. (70° C.) so that the coolant can heat the oil again.

The specified temperature values for closing the shut-off valves of the transmission heat exchangers vary depending on the operating condition/variant.

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2

• Driving program: Normal (moderate driving) • Coolant temperature = 221° F. (105°C)

2_521_11

The map-controlled thermostat (11) automatically begins to open at approx. 216° F. (102° C), providing a small gap for the coolant. From now on, the coolant is cooled by the coolant radiators (1, 2) in the front end. The setpoint coolant temperature in the engine is 221° F. (105°C) with a moderate driving style and Sport/Sport Plus mode deactivated.

Shut-off valve for gear oil heat exchanger and ATF heat exchanger (Porsche Doppelkupplung [PDK] only) The shut-off valves for the gear oil and ATF heat exchangers are only opened in this operating condition if the gear oil temperature and/or the ATF temperature are too low (e.g. in cold countries), or their temperatures are higher than that of the engine coolant, resulting in cooling of the heat exchangers at the transmission (8, 9).

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DME engine electronics

Sixth operating condition: At operating temperature

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911 Carrera 911 Carrera S

Seventh operating condition: At operating temperature • Driving program: Sport/Sport Plus, or: performance-oriented driving in the Normal program

DME engine electronics

• Coolant temperature approx. 185° F. (85° C.)

2

1 Side radiator 2 Center radiator, variants for extremely hot countries only (Not for USA) 3 Heat exchanger 4 Disc valve, vacuum-controlled 6 Coolant expansion tank 7 Engine oil heat exchanger

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5 Comfort valve

8 ATF heat exchanger (Porsche Doppelkupplung [PDK] only) 9 Gear oil heat exchanger 2_522_11

10 Engine coolant shut-off valve 11 Map-controlled thermostat 12 Coolant pump (mechanical)

The coolant temperature is reduced to 185° F. (85° C.) in Sport/Sport Plus mode

13 Engine coolant temperature sensor

and with a sporty driving style in Normal mode in order to improve the performance

14 Coolant temperature sensor,

values through improved charging.

Map-controlled thermostat The temperature reduction is achieved by heating and therefore opening the

radiator outlet

map-controlled thermostat (11). The map-controlled thermostat is completely open at an expansion element temperature of 239° F. (115 °C) (does not have to correspond to the coolant temperature).

Transmission cooling The shut-off valves for the gear oil heat exchanger (9) and ATF heat exchanger (8) are additionally opened if necessary in order to reduce the operating fluid temperatures in the transmission and in this way prevent overheating of the transmission parts.

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2

• Coolant temperature > 221° F. (105° C.)

2_523_11

If the setpoint coolant temperature at the engine and coolant outlet (depending on the operating condition) is exceeded despite the thermostat (11) being open, the engine coolant shut-off valve (10) is closed in order to increase the coolant throughput in the coolant radiators. The DME control unit opens the shut-off valve for the heat exchanger (4) via a command to the air conditioner control unit even if no heating request is present. The additional coolant and the heat emitted by the heat exchanger boost the engine cooling, and if necessary the cooling of the transmission. The coolant pressure is reduced at the same time by opening the shut-off valve for the heat exchanger. The cooling performance of the air conditioner increases in this operating condition because the passenger compartment has to be additionally cooled in order to keep the temperature in the passenger compartment constant. The DME control unit has the two electric fan motors running at maximum speed due to the high coolant temperatures at the coolant outlet.

Porsche Doppelkupplung (PDK) excess temperature The PDK control unit can request a torque reduction from the DME control unit if transmission temperatures are too high in order to prevent the transmission from overheating. The torque reduction ceases once the transmission temperature is no longer critical.

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DME engine electronics

Eighth operating condition: Maximum cooling

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911 Carrera 911 Carrera S

Coolant radiators DME engine electronics

2

1 Left coolant radiator with electric fan 2 Center coolant radiator (extremely hot countries only) (Not for USA) 3 Right coolant radiator with electric fan 4 Coolant expansion tank

Electric fans for coolant radiators The coolant radiators with electric fans (1, 3) are installed on both sides in the front end of the vehicle. The variants intended for extremely hot countries are equipped with a third, center additional radiator (2) (Not for USA) without an electric fan.

The functions of the electric fans are to • respond to cooling requests from the DME control (reduce engine coolant temperature, reduce air conditioner refrigerant temperature), • provide maximum cooling (emergency operation, n = 2,400 rpm) if there is no DME information available, • switch themselves off if there is a risk of damage from overheating.

The fan motors are phase-controlled synchronous motors that are continuously

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2_524_11

actuated via separate control units (drivers). The fan motors are most efficient at n = 1,800 rpm. The drivers required for operation of the fan motors receive their commands from the DME control unit by means of PWM signals and form one unit with the fan motor.

The 12V power supply for the fan motor is provided via a common line that also supplies the control unit mounted on it with current.

Diagnosis Both the control units of the radiator fans and the DME control unit can detect faults in the fans and insufficient cooling performance (radiator covered/dirty/air inclusions in the cooling system) and store them in the fault memory of the DME control unit.

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DME engine electronics

2

Electrical faults The radiator control unit detects electrical faults. If a short circuit/open circuit occurs, a fault entry is made in the DME control unit and the fans are no longer actuated.

The fan motors are operated in emergency mode (maximum speed) if the drive CAN

!

bus is faulty or a fan control unit is not receiving any signal from the DME control unit.

applying an external power supply, as this

Measuring the current consumption not only provides a way of detecting short

can damage the motors.

circuits, but also stiff/mechanically blocked fan motors.

Overheating/mechanical faults The radiator fan control units have an integrated temperature sensor. The fan control unit can detect overheating of a fan motor by means of the signal from the temperature sensor and switch off the fan (temporarily) (component protection).

The fan control unit can initiate measures (e.g. radiator fan motor working loose, operating the radiator fan at reduced speed) in the event of mechanical faults.

Inputs and outputs for thermal management control DME inputs • Engine power • Engine torque • Engine speed

Outputs

• Engine coolant temperature

• Map-controlled thermostat

• Coolant temperature,

• Engine coolant shut-off valve • Shut-off valve for heat

radiator outlet

exchanger

• Oil temperature

• Shut-off valve for gear oil

CAN inputs • Heating request via air conditioning control unit • Request for ATF cooling via transmission control unit (Porsche Doppelkupplung [PDK] only) • Ambient temperature via air conditioning control unit • Sport/Sport Plus mode via air conditioning control unit 2_525_11

78

DME control unit

heat exchanger • Shut-off valve for ATF heat exchanger (Porsche Doppelkupplung [PDK] only) • Coolant radiator fan motors

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The fan motors must not be tested by

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911 Carrera 911 Carrera S

Engine compartment purge fan The engine compartment purge fan consists of two electrically actuated fans. The fan motors can be operated at two speed settings (low and high) and are switched using two relays.

DME engine electronics

2

2_526_11

one relay for each of the two settings (low/high). The fan motors are actuated on the instruction of the DME control unit. Actuation takes place as a function of the engine compartment temperature, which is detected by a separate engine compartment temperature sensor. The engine compartment temperature sensor is connected to the DME control unit. Another variable is the engine coolanttemperature.

Operating condition: Engine off, ignition on The engine compartment purge fan runs at setting 2 when the engine compartment temperature is > 162° F. (72° C.). It switches off again under these conditions when the engine temperature is < 154° F. (68° C.).

Operating condition: Engine on When the engine is running, fan setting 1 is switched on when the engine

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The engine compartment fan motors do not have their own control unit. There is

compartment temperature is > 75° F. (24° C.) and switched off again when the engine temperature is < 59° F. (15° C.).

Fan setting 2 is switched on when the engine compartment temperature is > 149° F. (65° C.) or the engine coolant temperature is > 226° F. (108° C.).

When the engine is running, fan setting 2 is switched off again when the engine compartment temperature is < 145° F. (63° C.) or the engine coolant temperature is < 221° F. (105° C.).

Fan setting 2 is activated in the event of heavy acceleration from standstill.

Activation depends on the speed with which the accelerator pedal is depressed and the accelerator pedal travel (depress fully). The same applies to the launch control start on vehicles with Porsche Doppelkupplung (PDK).

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DME engine electronics

2

Operating condition: Engine switched off If the engine has been switched off, the fans can run for up to 25 minutes in order to purge the engine compartment.

Setting 2 runs at an engine temperature > 180° F. (82° C.) until the temperature in the engine compartment has fallen to < 158° f. (70° C.). The fan motors run at fan setting 1 until the engine temperature is < 113° F. (45° C.) in order to reduce the temperature further.

Operating condition: Interruption of fan operation Fan operation is interrupted if any of the following situations occur:

• Cabriolet only: convertible top open • Battery voltage < 10 volts

Diagnosis The engine compartment purge fan can be diagnosed using the DME control unit.

Drive-link diagnosis is possible using PIWIS Tester II. Detected faults are stored in the DME control unit.

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• Engine compartment lid open

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2012 911 Section 3-1 11/3/11 10:18 AM Page 82

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3 Power transmission

3.1 General The 911 Carrera (991) features a 7-speed manual transmission as standard, which is unique in the sports car segment. The transmission is essentially derived from

Power Transmission

the Porsche Doppelkupplung (PDK), with the gear ratio of the 3rd and 7th gears adapted to take account of the manual gear changes. The 3rd gear has a higher

3

ratio, which reduces consumption. The 7th gear has a lower ratio to maintain the tractive force even at comparatively low speeds.

The optional Porsche Doppelkupplung (PDK) is based on the unit familiar from the previous models, but has been systematically enhanced for the new 911 Carrera. It combines the sportiness of a manual transmission with the comfort of an automatic

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transmission, while further improving efficiency.

3_01_11

On the following pages you will find a description of the 7-speed manual transmission, followed by a description of the changes in the area of the double-clutch transmission.

General

83

7-speed Porsche Doppelkupplung

Clutch

84

(PDK)

99

7-speed manual transmission

84

General

99

Technical data G91/00

84

Coasting function

99

Shift mechanism

85

Neutral via paddle

101

Locking

89

Auto Start Stop system

102

Gearshift lock for 7th gear

91

Thermal management/lubricating

Gear wheel set

92

oil supply

Synchronization

94

Controlled rear differential lock

Drive

95

(CRDL)

106

Differential lock

95

Wiring harness

107

Oil circuit

96

Transmission control unit

109

Neutral detection sensor

98

Porsche Doppelkupplung (PDK)

109

103

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911 Carrera 911 Carrera S

3a Clutch Power Transmission

3

The self-adjusting single-plate dry clutch has a clutch plate diameter of 240 mm and has been adopted unchanged from the predecessor (see Fig. 3_02_11).

3b 7-speed manual transmission

3_02_11

Number of gears

7

Center distance

85 mm

Spacing/spread

5.5

Power transmission

450 Nm

Filling capacity

3.5 qts (3.3 liters)

Weight without DMF

190 lbs (86.1 kg)

without clutch Additional weight for differential lock 4.4 lbs (2.0 kg)

Transmission ratios:

84

Gear

igang

igang

ikonst.

i

1

11/43

3.909

1.114

3.091

13.464

2

24/55

2.292

1.114

3.091

7.893

3

29/45

1.552

1.114

3.091

5.344

4

33/43

1.303

1.114

3.091

4.488

5

37/40

1.081

1.114

3.091

3.723

6

42/37

0.801

1.114

3.091

3.034

7

45/32

0.711

1.114

3.091

2.449

R

11/39

3.545

1.114

3.091

12.211

Constant

35/39

1.114

3.091

3.444

Final-drive ratio

11/34

1.114

3.091

3.444

Achse

iges.

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3b.1 Technical data G91/00

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911 Carrera 911 Carrera S

Power Transmission

3_03_11

The G91/00 is a manual transmission with seven forward gears and one reverse gear. Shifting is performed via two cable mechanisms. One cable is used for selection, the other for shifting. The shifting follows an 'H' shift pattern.

Since the manual transmission is based on the Porsche Doppelkupplung (PDK) and the gears in the PDK are not positioned in an opposed arrangement, a completely new internal gearshift mechanism had to be developed.

The aim with the new internal gearshift mechanism is to convert the shift pattern to the H pattern.

Shift pattern without MECOSA

Shift pattern with MECOSA

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3b.2 Shift mechanism

3_04_11

The mechanism used to perform the conversion is called "MEchanically COnverted Shift Actuator" (MECOSA)

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911 Carrera 911 Carrera S

Power Transmission

3

MECOSA MECOSA produces a logical and familiar 'H' shift pattern for the driver from the random gear layout in the transmission gear wheel set. The main component in the gearshift mechanism is the actuator shaft, which can perform both translatory (straight) and rotary (turning) movements. The movements of the actuator shaft are realised by means of external cables and are transmitted to the transmission by the lever mechanism on the shift cover. The axial movement is used for selecting the gate and the rotary movement for shifting. The shift forks are connected to the individual shift frames via the shift rods. As shown in Fig. 3_46_11, the special layout of the shift fingers on the actuator shaft means that when shifting from 1st to 2nd gear, the rotation simultaneously moves the shift frames of the respective

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gears.

Disengaging 1st gear

Engaging 2nd gear 3_46_11

!

The shift frames are welded to the shift rods (Fig. 3_05_11).

Actuator shaft

86

Shift frames

3_05_11

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911 Carrera 911 Carrera S

Internal gearshift mechanism The shifting shaft is located in the recesses on the shift rods. There is a gate guide attached to the shifting shaft to ensure extremely precise shifting.

3 cardiagn.com

Power Transmission

3_07_11

The shift rods illustrated above (Fig. 3_07_11) show that unlike with conventional manual transmissions, the shift forks have to be moved in the same direction when changing gear (e.g. from 1st to 2nd).

Gate guide

3_22_11

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911 Carrera 911 Carrera S

3

3_06_11

Locking lever (selecting)

Locking lever (shifting)

3_08_11

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Power Transmission

Internal gearshift mechanism

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911 Carrera 911 Carrera S

3b.3 Locking The actuator shaft and shift frames also provide a locking function, which prevents multiple gears being engaged at the same time. The locking system of the transmis-

Power Transmission

sion works "actively", i.e. once a gate has been selected, the locking elements (locking cams) of the actuator shaft lock the shift frames of the gears that are

3

outside the selected gate.

locked

locked

can be engaged

3_47_11

The shift lever is in gate 3/4 when it is in neutral position.

Neutral position

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can be engaged

3_10_11

3rd or 4th gear can be engaged from the neutral gate, all other gears are locked.

The rotary movement that occurs during shifting engages the gear opposite the green check mark.

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911 Carrera 911 Carrera S

3

Gate 1/2

3_11_11

Gate 5/6

3_12_11

Gate 7

3_13_11

!

The rotary movement that occurs during shifting engages the gear opposite the green check mark.

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Power Transmission

Locking in different shift gates

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911 Carrera 911 Carrera S

3b.4 Gearshift lock for 7th gear A special gearshift lock has been developed to prevent undesired shifting into 7th gear.

Power Transmission

3

1 Fit bolt 2 Closure cap 3 Bush 4 Spring 5 Locking ring

3_14_11

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6 Actuator shaft

The 7th gear gate can only be selected if the 5th or 6th gear was engaged

Gate 3/4 selected => locking ring is

previously. Downshifting can take place as desired.

decoupled 1 mm from the actuator shaft.

Gate 5/6 selected => actuator shaft Gate 3/4

Gate 5/6

Gate 5/6

Gate 7

selected

selected

selected

selected

pushes the locking ring upwards and blocks gate 7.

5th or 6th gear engaged => actuator

shaft rotates by 29° => locking ring slides back in axial direction and releases gate 7.

5th or 6th gear disengaged => actuator shaft rotates back into neutral 3_15_11

position => locking ring is radially preloaded via torsion spring.

Selecting gate 7 => actuator shaft pushes the locking ring upwards.

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911 Carrera 911 Carrera S

Power Transmission

3

3b.5 Gear wheel set

1 Input shaft 2 Intermediate gear wheel 3 Pinion shaft with constant transmission ratio

3_16_11

The gear wheel set in the transmission comprises the input shaft (1), main shaft (4), pinion shaft with constant transmission ratio (3) and intermediate gear wheel (2).

Structure of the input shaft

1

Loose gear wheel for 4th gear

2

4/6 shift sleeve

3

Loose gear wheel for 6th gear

4

Cylindrical-roller bearing

5

Fixed gear wheel for 2nd gear

6

Fixed gear wheel for reverse gear

7

Fixed gear wheel for 1st gear

8

Fixed gear wheel for 3rd gear

9

Loose gear wheel for 7th gear

10 5/7 shift sleeve 11 Loose gear wheel for 5th gear 3_17_11

The input shaft lies above the main shaft and is supported by 3 bearings.

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4 Main shaft

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911 Carrera 911 Carrera S

Structure of the main shaft Power Transmission

1

Fixed gear wheel for 4th gear

2

Spacer

3

Fixed gear wheel for 6th gear

4

Constant gear wheel

5

Bearing

6

Loose gear wheel for 2nd gear

7

R/2 shift sleeve

8

Loose gear wheel for reverse gear

9

Loose gear wheel for 1st gear

10 1/3 shift sleeve

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3_18_11

3

11 Loose gear wheel for 3rd gear 12 Fixed gear wheel for 7th gear

The main shaft lies beneath the input shaft and is supported by 3 bearings.

13 Spacer

14 Fixed gear wheel for 5th gear

3_19_11

The change in direction for reverse gear is accomplished via an intermediate gear wheel (1), which is located between the input shaft and main shaft.

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911 Carrera 911 Carrera S

Power Transmission

3

3b.6 Synchronization Synchronization of reverse, 1st, 2nd and 3rd gear Triple cone synchronizers with carbon coatings (1st, 2nd, 3rd gear) and a single cone scatter sinter coating (reverse gear) are used. The use of three friction cones has resulted in a significant reduction in synchronizing forces. This reduces shifting forces when engaging gears.

The first friction cone comprises the friction cone of the clutch hub of the loose gear wheel (4) and the inner cone of the inner ring (3). The second friction cone comprises the outer cone of the inner ring (3) and the inner cone of the intermediate ring (2). The third friction cone comprises the outer cone of the

1 Synchronizer ring 2 Intermediate ring 3 Inner ring 4 Loose gear wheel

3_20_11

1 Synchronizer ring 2 Loose gear wheel

3_21_11

Synchronization of 4th, 5th, 6th and 7th gear Single-cone servo-lock synchronizers with carbon friction coating are used for 4th, 5th, 6th and 7th gear. The cones of the clutch hub (2) and the cones of the synchronizer rings (1) form the friction cones.

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intermediate ring (2) and the inner cone of the synchronizer ring (1).

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911 Carrera 911 Carrera S

3b.7 Drive Power Transmission

3

A Direction of travel B Direction of rotation

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C Output flange

3_23_11

The power is transmitted from the engine to the transmission via the input shaft.

From the transmission it travels via the respective gear ratio from the input shaft above the main shaft to the pinion shaft with its constant transmission ratio. The change in direction of the power/engine speed from longitudinal to transverse direction also takes place via the final-drive ratio. The power is output via the axle flange on the halfshafts and finally to the drive wheels.

3b.8 Differential lock The manual transmission can be equipped with a differential lock as an option. The locking value is 22% (traction) and 27% (deceleration).

1 Ring gear 2 Differential pinions 3 Shaft bevel gears 4 Planet-gear carrier 5 Discs 6 Pinion

3_24_11

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911 Carrera 911 Carrera S

Power Transmission

3

3b.9 Oil circuit Oil types and oil quantities The transmission is filled with 3.5 qts (3.3 liters) of Mobilube PTX 75W - 90, the change interval for the transmission oil is 112,000 miles (180,000 km).

Oil cooling The transmission has a separate oil-water heat exchanger (1) that can both heat up

2 1 3_26_11

1 Oil-water heat exchanger 3_25_11

2 Gear oil pump

The heat exchanger (1) is installed on the outside of the transmission, the gear oil pump (2) is installed directly on the heat exchanger. The gear oil pump is driven by the pinion shaft, which means that the supply of cooling oil to the gear wheel set is speed-dependent.

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and cool down the gear wheel oil.

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911 Carrera 911 Carrera S

Temperature sensor

3

The temperature sensor (1) for the gear wheel chamber is used to detect the temperature of the gear wheel oil. It is a temperature-dependent resistor that is

Power Transmission

screwed into the transmission from the outside. The temperature sensor communicates with the engine control module and is implemented in the vehicle thermal

3_48_11

Resistance (ohms)

R nominal

Temperature (°C)

Temperature

Resistance

T

R

°C

kΩ

- 40.00

104.81

- 20.00

35.834

0.00

13.968

20.00

6.068

25.00

5.000

40.00

2.887

50.00

2.051

60,00

1.484

80.00

0.814

100.00

0.473

120.00

0.289

140.00

0.184

160.00

0.122

180.00

0.084

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management system.

3_27_11

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911 Carrera 911 Carrera S

3

The neutral detection sensor is used to detect the neutral position of the transmission. Auto Start Stop can only be activated when no gear is engaged.

1 Sensor magnet fitted in the cover: The sensor magnet scans the Hall element. The change in the magnetic field lines is detected through the shift cover.

2 Sensor magnet visible: The sensor magnet is permanently 3_28_11

moulded onto the locking lever. This means there can be no change in its position over its service life.

3 Neutral detection sensor

The change in the direction of the magnetic field is detected by way of a Hall-effect sensor. The electronics integrated in the sensor convert the detected signal into a pulse-width-modulated (PWM) signal and output it to the engine control module.

3_29_11

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Power Transmission

3b.10 Neutral detection sensor

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911 Carrera 911 Carrera S

3c 7-speed Porsche Doppelkupplung (PDK) 3c.1 General The optional Porsche Doppelkupplung (PDK) type CG1.05 is based on the unit familiar from the previous models, but has been systematically enhanced for the

Power Transmission

3

new 911 Carrera. It combines the sportiness of a manual transmission with the comfort of an automatic transmission, while further improving efficiency and reducing shifting times.

Overview of changes • Coasting function (section 3c.2)

• Integration of the Auto Start Stop system (section 3c.4) • Thermal management and lubricating oil supply (section 3c.5) • Controlled rear differential lock (CRDL) (section 3c.6) • Modified wiring harness (section 3c.7) • Modified control unit (ETC) (section 3c.8) • Redesigned double-clutch transmission (section 3c.9)

3c.2 Coasting function The new 911 Carrera models now feature the coasting function in conjunction with the Porsche Doppelkupplung (PDK). The purpose of coasting is to make better use of the vehicle's kinetic energy. This is done by automatically disengaging the engine and keeping it at idle speed when the vehicle is in zero load condition (accelerator pedal not pressed). This allows the vehicle to roll an additional distance without using any fuel. The fuel saving during practical driving therefore comes from the

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• Neutral via paddle (section 3c.3)

fact that the vehicle's kinetic energy is only used to overcome the rolling and air resistance and no longer to drag along the engine at high engine speeds.

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911 Carrera 911 Carrera S

Power Transmission

3

Vehicle speed V1 = 100 km/h

Steady driving Overrun

(62 mph)

Coasting

V2 = 80 km/h

Distance

(50 mph)

!

Driving situation shown in the graphic:

Consumption with steady driving and overrun

Consumption with steady driving

Overrun, no injection

The driver wants to reduce the vehicle speed from 62 mph (100 km/h to

Consumption during idling

3_30_11

a.) Vehicle without coasting function:

If the driver indicates a wish to decelerate by pressing the brake or intervenes

Steady driving and then braking with

manually by pressing the downshift button, the engine is re-engaged in order to use

engine deceleration (without fuel injection)

the engine's trailing throttle fuel cutoff; the fuel supply is interrupted during this

(red curve)

process and the engine braking effect shortens the vehicle's stopping distance once more.

b.) Vehicle with coasting function: Activation coasting mode and deceleration

Coasting is automatically prevented in driving situations where it no longer makes

at idle speed fuel consumption

sense or would be counterproductive: if the vehicle speeds up on steep downhill

(green curve).

gradients despite trailing throttle fuel cutoff, it is better to exploit the full fuel saving produced through trailing throttle fuel cutoff. The coasting phase would be too short

The driving curve with coasting is more

in the case of steep uphill gradients. Coasting is suppressed during sporty driving

fuel efficient because the total idle speed

so as to enable more direct responsiveness and not interrupt the flow of driving with

consumption during the coasting phase

frequent disengagement and engagement.

(green block) is less than the total consumption during steady driving (red

The driver can also actively suppress coasting by quickly removing his/her foot

block). This also works with much smaller

from the accelerator pedal (e.g. approaching a bend, aborting a passing attempt).

differences in speed (< 3 mph (5 km/h)

Coasting can also be triggered when specifically desired by the driver by pressing

and in other driving situations, e.g. slight

the upshift button in the highest gear (accelerator pedal not pressed). Engagement

downhill gradients.

takes place automatically during acceleration.

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50 mph (80 km/h).

2012 911 Section 3-1 11/3/11 10:18 AM Page 101

911 Carrera 911 Carrera S

Prerequisites for coasting mode • Driving in selector-lever position D • Coasting mode is switched on (Auto Start Stop not deactivated using switch) • Sport or Sport Plus mode is deactivated • PSM is active

Power Transmission

3

• Engine, transmission and battery have reached operating temperature • Relaxed/economic driving style • Slight uphill or downhill gradient • Remove foot slowly from the accelerator pedal

•

Press the accelerator pedal or

•

Press the brake pedal or

•

Change gears using the selector lever

Coasting mode can be deactivated using the Auto Start Stop switch.

3c.3 Neutral via paddle A further special function (neutral via paddle) is available if the vehicle is equipped with the optionally available paddle steering wheel. If both shift paddles are pulled simultaneously and then released again, the active clutch is opened and the transmission is disengaged from the engine.

The number disappears from the gear indicator and the selector-lever position displayed in the instrument cluster flashes.

Power transmission can be re-established by pulling one of the shift paddles or by

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Ending coasting mode

actuating the selector lever.

At low speeds approaching standstill, the brake must also be actuated in order to establish power transmission.

This function makes it possible to quickly disconnect the power transmission between the engine and transmission.

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911 Carrera 911 Carrera S

A Check valve

3

The 911 Carrera vehicles as of model year 2012 feature an Auto Start Stop system. There is an additional check valve installed in the hydraulic control unit so that the clutches and oil supply ducts do not drain when the engine is switched off.

3_32_11

Check valve

3_31_11

!

Due to the modification of the additional

The "Quickstart" function supplies hydraulic pressure oil to the clutches while the

shut-off the hydraulic control unit must

engine is starting so that the power transmission can be established without delay

on no account be replaced with one

when the engine is restarting.

without check valve (or vice versa).

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Power Transmission

3c.4 Auto Start Stop system

2012 911 Section 3-1 11/3/11 10:18 AM Page 103

911 Carrera 911 Carrera S

3c.5 Thermal management/lubricating oil supply

3

Power Transmission

3

1

2

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4

3_34_11

1 Heat exchanger 3_33_11

2 Oil pump position

The Porsche Doppelkupplung (PDK) transmission has a separate heat exchanger

3 Lubricating oil supply pipe

whose sensors are integrated in the thermal management system for the entire

4 Pinion shaft

vehicle.

The heat exchanger has two main tasks: • Heat up the gear wheel oil faster for better efficiency • Cool the gear oil as required The heat exchanger (1) is installed on the outside of the transmission. The gear oil pump (2) is installed beneath it. It is driven by the pinion shaft (4) and is therefore speed-sensitive. The purpose of the pipe (3) fitted to the gear oil pump is to supply lubricating oil to the controlled rear differential lock (CRDL). On transmission types without CRDL, the lubricating oil is delivered by a hollow-bore pinion shaft into the differential chamber.

The supply of cooling oil to the gear wheel set is also performed by way of the trochoid pump installed directly at the radiator (1) (Fig. 3_35_11).

Temperature sensor Like the manual transmission, the Porsche Doppelkupplung (PDK) transmission also

3_35_11

features a temperature sensor to detect the temperature of the gear oil. The function and installation position is the same as on the manual transmission.

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911 Carrera 911 Carrera S

3

from the predecessor with slight changes to the line routing.

3_49_11

3_43_11

Oil supply to the differential Since the Porsche Doppelkupplung (PDK) with controlled rear differential lock has an external line for lubricating the CRDL, the bore in the pinion shaft (1) is sealed by the pump drive shaft (2).

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Power Transmission

The oil cooler for the hydraulic fluid (1) together with its lines has been adopted

2012 911 Section 3-1 11/3/11 10:18 AM Page 105

911 Carrera 911 Carrera S

On the version without CRDL, the oil to lubricate the differential chamber is routed

pinion shaft into the differential chamber.

Power Transmission

3_44_11

Filler and drain plugs for the gear wheel chamber

!

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3

from the pump via the hollow pump drive shaft and directly via the hollow-bore

The target oil level within the oil chamber for the gear wheel set/bevel gear is 10

mm higher in the differential area than in the rest of the gear wheel set. This

means that the differential oil level is also higher than the inspection/filler opening, which results in a special filling procedure.

A description of this procedure can be found in the Workshop Manual and must be followed exactly.

1

Inspection and filler opening

2

Drain plug for gear wheel chamber

3

Drain plug for differential chamber

3_36_11

The transmission has two separate oil chambers since different oils are used for the hydraulic components and the gear wheel set/bevel gear.

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911 Carrera 911 Carrera S

Power Transmission

3

3c.6 Controlled rear differential lock (CRDL) Unlike the previous models, in which only one locking differential was available to additionally support the driving dynamics, Porsche Torque Vectoring/Plus (PTV/PTV Plus) now provides a much improved product feature for all transmission variants.

The 911 Carrera S is equipped with PTV/PTV Plus as standard. PTV/PTV Plus is available as an option for the 911 Carrera. PTV features a locking differential with asymmetrical locking action (22% traction and 27% deceleration) and is available in conjunction with the standard 7-speed manual transmission.

PTV Plus features a fully variable electronic rear differential lock and is only available

1

Pressure pin (8x)

2

Thrust washer

3

Piston

4

Diaphragm seal

5

Hydraulic oil chamber

6

Cup spring

7

Gear wheel oil chamber

8

Hydraulic oil pressure duct

9

Disc pack

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in conjunction with the Porsche Doppelkupplung (PDK).

10 Compression spring, 4x arranged staggered around the circumference

3_37_11

Depending on the pressure applied in the pressure duct (8), the thrust washer (2) is pressed onto the the disc pack (9) by the cup spring (6) via the eight pressure pins and in this way achieve a locking value dependent on the pressure. This value is absolutely variable from 0 to 100%.

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911 Carrera 911 Carrera S

Hydraulic system An additional hydraulic control block is installed in the transmission for supplying oil pressure to the controlled rear differential lock; this control block is connected to

Power Transmission

the hydraulic control system and the CRDL by way of pipes and is integrated in the control and wiring harness system via an electric pressure adjuster (EDS 7). It is

3

mounted on the centering plate.

1 Feed line 2 Control block 3 Vent for CRDL clutch chamber 5 EDS 7 6 Pressure sensor for CRDL

3_38_11

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4 Pressure line for CRDL

6

3c.7 Wiring harness Since an additional electrical pressure control valve (EDS) can be installed for the controlled rear differential lock, the wiring harness and the routing has changed compared with the previous model. There is also an additional connection for the

1

temperature sensor for the gear wheel oil.

5 2 3_39_11

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911 Carrera 911 Carrera S

3

The transmission control unit is inserted in the heel plate (underneath the rear seat on the right) with a holder and fastened with a screw.

3_41_11

!

The plug connections are identical with

Control unit shown in brown

3_40_11

the predecessor control unit, but must not be interchanged under any circumstances.

Technical data for the control unit: CPU: TriCore TC1767 (32 bit) Clock speed: 128 MHz RAM: 88 k (usable) 3_42_11

ROM: 2 MB (flash)

The control unit has been switched to lead-free solder to comply with environmental regulations.

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Power Transmission

3c.8 Transmission control unit

2012 911 Section 3-1 11/3/11 10:18 AM Page 109

911 Carrera 911 Carrera S

3c.9 Porsche Doppelkupplung (PDK) Power Transmission

3

1 Steel outer discs 2 Coated inner discs 3 Oil supply grooves example) 5 Cooling oil grooves 3_45_11

The drive-off quality has been further improved thanks to a number of minor modifications in the area of the Porsche Doppelkupplung (PDK) such as: • New surface for the steel discs (1) • Modified coating of the inner discs (2) • Slightly wider oil supply grooves (3) • Seals with larger concentricity tolerances (4) • Changeover in the production of the cooling oil grooves (5)

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4 Inner seals (just one indicated as an

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911 Carrera 911 Carrera S

4 Chassis

4.1 General The concept used for the chassis makes a decisive contribution to the handling characteristics of a vehicle. The demands for the new 911 Carrera models were

Chassis

particularly high, since in addition to the important aim of ensuring outstanding comfort and day-to-day usability, the development goals included achieving best-in-

4

class performance for even better driving dynamics and agility.

In order to achieve these goals, all chassis variants of the new 911 Carrera models have been enhanced. In addition to fundamental design modifications on the front and rear axles, features include the enhanced Porsche Active Suspension Management (PASM), the PASM sports chassis (-20 mm), the new Porsche Dynamic Chassis Control (PDCC), the completely new electromechanical power steering, the

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revised brake system as well as the new wheels.

4_01_11

General

111

Brake system

143

Front axle

114

Electric parking brake

144

Rear axle

117

Porsche Stability Management

148

Power steering

119

Porsche Torque Vectoring

153

Dynamic engine mountings

127

Porsche Active Suspension Management

130

Porsche Dynamic Chassis Control

133

Wheels and tires

140

Tire pressure monitoring

141

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911 Carrera 911 Carrera S

Chassis

4

Starting from the previous models, the main development goals in the area of the chassis for the new 911 Carrera models were as follows: • Extension of the wheelbase by 3.9˝ (100 mm) • Increased track width on the front axle (911 Carrera by 1.8˝ (46 mm), 911 Carrera S by 2˝ (52 mm) • Redesign of the front and rear axle with optimized kinematics and elasto-kinematics • Improvement of the PASM function with four additional height sensors • Porsche Dynamic Chassis Control (PDCC) • Electromechanical power steering • Electric steering column adjustment

enhanced rolling comfort • Comfort air pressure • Sport button as standard • Sport Chrono package including dynamic engine mounting • Porsche Torque Vectoring/Plus (PTV/PTV Plus) with mechanical/electronically controlled rear differential lock

Longer wheelbase and wider track at the front Significantly improved driving stability, particularly at high longitudinal and cornering speeds, was achieved by modifying the vehicle dimensions. At the same time, the compact external dimensions that are typical of the sports car were retained. The wheelbase was extended by 3.9˝ (100 mm) with an increase of only 2.2˝ (56 mm) in the vehicle length. The track width at the front was increased by 1.8˝ (46 mm) for the 911 Carrera and 2˝ (52 mm) for the 911 Carrera S, while the vehicle width at the front was extended by 2.4˝ (61 mm). The vehicle width at the rear and therefore the overall vehicle width has been retained.

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• New generation of tires with larger rolling circumference (+ 4%) and

2012 911 Section 4-1 11/3/11 10:19 AM Page 113

911 Carrera 911 Carrera S

Chassis

Wider front axle of the 911 Carrera S

4 cardiagn.com

Wider front axle of the 911 Carrera

Chassis variants Like the previous models, the new 911 Carrera and 911 Carrera S have different chassis variants. In addition to the basic chassis, two further chassis options are available for the 911 Carrera: the variable Porsche Active Suspension Management (PASM) damper system with chassis lowered by approx. 10 mm as well as the

4_03_11

PASM sports chassis (with chassis lowered by 20 mm and mechanical/electronic rear differential lock).

The 911 Carrera S features the PASM chassis as standard (10 mm lower than the basic 911 Carrera chassis) and is optionally also available with the PASM sports chassis (lowered by an additional 10 mm and mechanical/electronic rear differential lock).

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911 Carrera 911 Carrera S

4

4_02_11

The redesigned front axle with optimized lightweight McPherson struts reduces the vehicle weight by 4.4 lbs (2 kg). The front-axle cross member was optimized with respect to crash and rigidity requirements. The increased anti-dive characteristic reduces diving at the front of the vehicle during full braking and shortens the braking distance. The track on the front axle is 2˝ (52 mm) wider on the 911

!

Carrera S and 1.8˝ (46 mm) wider on the 911 Carrera for additional driving stability and agility during cornering.

The technical data is intended to provide an overview only. As it is subject to

Front-axle cross member

change in the course of the model year,

The front-axle cross member has been newly developed for the 911 Carrera/

the data published in the PIWIS

Carrera S. The geometry has been completely revised based on rigidity and crash

information system always takes

requirements. To increase the track width, the axle attachment points of the lower

precedence.

control arm plane were moved out by 18 mm on each side in the case of the control arm and by 13 mm in the case of the trailing arm.

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Chassis

4.2 Front axle

2012 911 Section 4-1 11/3/11 10:19 AM Page 115

911 Carrera 911 Carrera S

Control arm The proven system from the previous model of the lower control arm plane with a control arm and a trailing arm on each side was retained and optimized in a number of details.

Chassis

4

A hydraulic mount in the control arm at its connection point to the trailing arm ensures that high-frequency vibrations are effectively suppressed during longitudinal movements, resulting in less disturbing influences on the steering and the vehicle body. The outer ball joint has been redesigned and modified specifically to achieve increased transverse rigidity without compromising on joint mobility.

The trailing arm design is based on crash and misuse requirements as well as the necessary wheel guidance characteristics. Its length is 13.7˝ (352 mm). For weightreduction purposes, an M12 screw (previously M14) is used for attachment to the body - as is now the case for all threaded joints between the front axle and the body. The front ball joint has been adapted accordingly.

Suspension strut The new lightweight suspension strut consists of a double-tube gas-filled shock absorber and a concentrically arranged coil spring, which is in turn adapted to the different vehicle variants.

Basic Carrera chassis

Spring rate: 24 N/mm

Carrera/Carrera S PASM chassis

Spring rate: 28 N/mm

Carrera/Carrera S PASM sports chassis

Spring rate: 33 N/mm

The springs are color-coded to indicate the spring tolerance and the chassis

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Trailing arm 4_04_11

4_05_11

version.

Wheel carrier To reduce weight, the wheel carrier is manufactured as a torsionally and flexurally rigid hollow-cast part. To optimize the flow of cooling air to the brakes, the geometry in the area of the steering arm is designed to allow ventilation via the brake air spoiler mounted on the trailing arm with minimal flow losses. The component is partially ribbed on the inside for noise reduction purposes.

Wheel bearing The proven system from the previous model with press-fit and additionally tensioned “first generation” wheel bearing is used in order to reliably transfer the increased

4_06_11

transmission forces generated by the higher performance (see Fig. 4_06_11). This concept has the advantage of very firm lateral wheel guidance combined with low weight, and therefore contributes to the very precise handling typical of a sports car.

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911 Carrera 911 Carrera S

Chassis

4

!

Anti-roll bars The diameter and thickness of the anti-roll bars have been designed to match the vehicle’s weight and driving dynamics. The following variants are installed:

911 Carrera Basic chassis

Tube 26.8 x 4.0 mm

PASM chassis

Tube 26.8 x 4.0 mm

PASM sports chassis (Coupé only)

Tube 28.0 x 4.0 mm

an overview only. As it is subject to

911 Carrera S

change in the course of the model year,

PASM chassis

Tube 26.8 x 4.0 mm

the data published in the PIWIS

PASM sports chassis (Coupé only)

Tube 28.0 x 4.0 mm

information system always takes precedence.

Axle geometry/kinematics The axle kinematics have been completely overhauled to improve driving dynamics and for the implementation of new systems (e.g. PDCC, electromechanical power steering). The axle adjustment values vary for the different variants (e.g. camber for 911 Carrera -0° 20 , 911 Carrera with PASM and 911 Carrera S -0° 35 as well as PASM sports chassis -0° 50 ). The kinematic toe-in adjustment is -10’ per 10 mm of compression travel, while the kinematic camber adjustment is -14’ per 10 mm of compression travel.

To maintain the same turning circle as in the previous model despite the 100 mm longer wheelbase, the steering kinematics were also adapted and the wheel angle increased accordingly at full steering lock. At the maximum steering angle, the turning circle is 33.39 ft (10.3 m) with an Ackermann value of 40%.

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This technical data is intended to provide

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911 Carrera 911 Carrera S

4.3 Rear axle The new multi-link rear axle design with increased supporting base ensures an optimum camber rate and toe-in rigidity. Optimized kinematics for longitudinal suspension in combination with a 5 mm increase in compression travel improve driving comfort. This was implemented with a new arrangement of the control arms. In the

Chassis

4

upper plane there are now three control arms, the upper control arms and the toe control arm, which are fastened to the side section. The lower plane consists of the control arm connected with the cross member and the diagonal control arm connected with the body via a mount.

The rolling noise has also been reduced by way of new, highly-elastic rubber/metal

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mount compounds in the control arms.

4_22_11

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4

The side section (1) is bolted directly to the body without rubber mounts. The upper control arms (2 and 3) and the toe control arm (4) are attached to the side section.

The track is adjusted via the eccentric adjusters (arrow in Fig. 4_56_11) at the threaded joint to the side section.

4_23_11

4_56_11

Rear-axle cross member and lower control arm plane The cross member (5) connects the left and right side sections and supports the 4_24_11

lower control arm (6). The threaded connection of the lower control arm features an eccentric adjuster for camber adjustment. The lower control arm (7) forms the connection between the wheel carrier and the body. To further reinforce the rear axle, diagonal struts (8) are mounted between the cross member and the body.

Wheel carrier To reduce weight, the wheel carrier is manufactured as a torsionally and flexurally rigid hollow-cast part.

Wheel bearing The wheel bearing is 5 mm wider compared with the previous model in order to reliably transfer the greater transmission forces generated by the higher perfor4_26_11

mance. The wheel bearing is press-fit into the housing and additionally tensioned by way of a cover.

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Chassis

Rear-axle side section and upper control arm plane

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911 Carrera 911 Carrera S

This concept has the advantage of very firm lateral wheel guidance combined with low weight, and therefore contributes to the very precise handling typical of a sports car.

Chassis

Suspension strut

4

The suspension strut consists of a single-tube gas-filled shock absorber and a coil spring, which in turn is adapted to the different vehicle variants. The springs are

Basic Carrera chassis

Spring rate: 48 N/mm

Carrera/Carrera S PASM chassis

Spring rate: 62 N/mm

Carrera/Carrera S PASM sports chassis

Spring rate: 108 N/mm

Axle geometry/kinematics The axle kinematics have been optimized to improve driving dynamics and for an optimum camber rate and toe-in rigidity. The camber values vary for the different variants (e.g. camber for 911 Carrera and 911 Carrera S -1° 30 , PASM sports chassis -1° 40 ). The kinematic toe-in adjustment is +2’ per 10 mm of compression travel, while the kinematic camber adjustment is -15’ per 10 mm of compression travel.

4.4 Power steering All 911 models feature a variable rack-and-pinion steering gear with speed-sensitive, electromechanical power steering with no hydraulic components.

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color-coded to indicate the spring tolerance and the chassis version.

4_27_11

4_07_11

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4

Compared with a hydraulic power steering system, this system offers the advantage of a reduction in fuel consumption. This is achieved thanks to the fact that energy is only required when the driver uses the steering. It also improves comfort and safety thanks to additional new functions.

Feedback is provided to the driver via the steering wheel and negative or unnecessary interference is filtered out. Active resetting of the steering ensures that the steering wheel automatically returns to the centre position even at low speeds.

When braking on road surfaces with different coefficients of friction under the left and right wheels, a steering pulse is output in the desired steering direction. This

course. As a result of extensive lightweight design measures (e.g. tie rods in aluminum and weight optimizations to many individual components), the weight of the new electromechanical power steering is practically the same as that of the previous hydraulic steering system.

Power steering Plus Power steering Plus, a speed-sensitive power-steering system, is available as an option for all 911 Carrera (991) models. At low speeds, Power steering Plus facilitates much easier and comfortable manoeuvring and parking. To ensure the typical Porsche steering response, requirements with regard to the basic mechanical design and electronic control quality have been significantly enhanced. The new power steering for the 911 Carrera models is characterised by a compact design, highly dynamic response and extremely precise steering in any driving situation.

Design and function of the power steering 1 Housing with steering rack 2 Steering spindle connection 3 Torque sensor 4 Steering pinion 5 Sensor cable 6 Electronic control unit 7 Electric motor 8 Power steering gear 4_08_11

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makes it easier for the driver to stabilize the vehicle and remain on his/her intended

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911 Carrera 911 Carrera S

The steering gear consists of the rack with pinion drive. The toothing of the rack is produced with different modules and meshing angles. This means, on the one hand, that the steering responds as usual in the center position (driving straight ahead).

Chassis

On the other hand, however, the steering ratio is smaller at larger torque angles (to

4

4_09_11

For steering assistance, the steering system features a DC motor with integrated control unit mounted parallel to the steering gear.

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the right and left) and the steering is therefore more direct.

1 Small toothed disc/electric motor 2 Toothed belt 3 Steering rack/ball thread

4 Large toothed disc/ball recirculating nut 5 Ball recirculating nut 6 Balls/ball chain 7 Return channel

4__10_11

To convert the rotational drive movement of the electric motor into linear movement of the steering rack (3), a paraxial drive in conjunction with a gear concept consisting of toothed belt drive (2) and recirculating ball gear is used. Both drive stages operate with a very high degree of efficiency. The ball thread drive uses a system with duct return. The ball chain (6) is returned via a duct integrated in the recirculating ball nut (5). The ball thread generates little noise during operation. This allows a rigid connection between the steering and the subframe of the vehicle, resulting in a very direct steering feel.

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4

Torque sensor The torque sensor measures the torque applied to the steering wheel by the driver.

The steering assistance of the engine is calculated in the control unit. The sensor (4) is located on the steering pinion (3). A magnetic ring is attached to the steering spindle (2), which is connected to the steering pinion via the torsion bar (1).

When the driver applies a torque to the steering wheel, the torsion bar rotates, as does the magnet for the sensor. The sensor consists of magnetoresistive elements, which change their resistance when there is a change in the field direction. The voltage range of the resistances when the magnet rotates produces a sinusoidal characteristic. The measuring range of the sensor extends from +/- 8 to +/- 10

1 Torsion bar

4_11_11

the torsion bar. Using this information, the steering torque and steering speed of

2 Steering spindle

the driver are calculated and transmitted as an electrical signal to the steering

3 Steering pinion

control unit.

4 Sensor unit

Control unit The control unit is mounted directly on the DC motor. The control unit has three connector interfaces. The battery connector (C) is used as the power supply for the control unit and for the DC motor.

The vehicle signal connector (B) is used as the interface for CAN communication and terminal 15. The torque signal connector (A) sets up the connection with the torque sensor.

4_12_11

A Torque signal connector

This calculates the required steering assistance from the data received and

1 Sensor signal

activates the servo motor if necessary.

2 Ground 3 Free

Connector assignment

4 Free 5 Free B Vehicle signal connector 6 CAN shield 7 CAN low 8 Free 9 Free 10 CAN high 11 Terminal 15 C Battery connector 12 B+ 13 B-4_13_11

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Nm. At higher steering torques, a mechanical angle limiter prevents overloading of

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911 Carrera 911 Carrera S

Operating principle

4

Steering assistance is activated when the combustion engine is started (rpm > 450 rpm). The steering torque applied by the driver is detected by the

Chassis

torque sensor and transmitted to the control unit. Using the steering torque and other input variables such as the steering angle and vehicle speed, the control unit calculates the necessary assistance torque, which is applied by the motor. The assistance torque generated by the motor is supplied to the steering rack via the

Control unit and sensors Battery sensor Battery voltage

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recirculating ball steering gear as an axial force.

Front-end electronics Terminal 15

Power supply B+ B–

PSM control unit Speed

Control unit

DME

for electric

Engine speed

power steering

Gateway

Start Stop

Driving dynamics control

Torque sensor

Instrument cluster

Torsion bar torque

Fault Failure

Combined steering column module

Steering angle

Electric motor for power steering B+ B–

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4

Steering pulse The new steering pulse for all 911 Carrera models is a safety-oriented driver assistance function, which assists the driver in certain driving situations (e.g. when braking on µ split). When braking on surfaces with different coefficients of friction, an undesired yawing moment can build up around the vertical axis of the vehicle. If the driver does not respond appropriately to this situation, a brief steering torque pulse is output in the corresponding steering direction in order to stabilize the vehicle. The driver intuitively steers in the direction stipulated by the pulse in order to ensure improved braking stability.

Without steering pulse Ice

•

Vehicle driving on µ split: E.g. right-hand side asphalt, left-hand side ice/water

•

Steering in straight-ahead position

•

Vehicle “pulls” to the right when µ is high

•

Experienced driver: immediate

Full braking

countersteering in the right direction

•

Inexperienced driver: failure by the driver to respond or a response that is too slow will

Stopping distance

result in reduced vehicle stability

With steering pulse •

Vehicle driving on µ split: e. g. right-hand side asphalt, left-hand side ice/water

Full braking

•

Steering in straight-ahead position

•

Vehicle “pulls” to the right when µ is high

•

Steering pulse: immediate countersteering in the right direction

•

Effect: the ABS set-up can be optimized for braking distance

Stopping distance

> Improved braking quality > Reduced stopping distance

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Asphalt

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911 Carrera 911 Carrera S

Safety and diagnosis

4

The driver is informed about a steering assistance failure or restricted steering assistance via the display on the instrument cluster.

Symbol

Failure Steering assistance

Fault Steering assistance

Meaning

Due to a fault, steering assistance is not available.

Message cannot be acknowledged

Due to a fault, only reduced steering assistance is available.

Message can be acknowledged

Teaching the end stops

!

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Message

Chassis

The steering end stops must be re-taught following replacement of the steering or

The end stop can assume the following

the entry of a new Vehicle Identification Number. For this purpose, the steering

three teach-in statuses:

wheel must be turned to the left-right stop when the vehicle is stationary or travelling slowly.

Learning status 0: Not learned.

Basic conditions:

Learning status 1: Learned when the

• Track is adjusted.

vehicle is stationary (workshop).

• The steering-angle sensor is calibrated.

• The steering system is fully installed in the vehicle, the connectors are attached.

Learning status 2: Learned when travelling slowly (fully taught).

• The vehicle is on a level surface. (Axles must not be relieved by the lifting platform.)

• The steering movement of the front wheels is not restricted by obstacles.

The teach-in status can go from status 0 via 1 to 2, or directly from status 0 to 2.

• The vehicle is stationary.

• The combustion engine is running.

The current teach-in status can be read

• The brake (incl. parking brake) is not applied.

out via the diagnosis function.

• The steering wheel is in the center position (straight-ahead).

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Power steering Plus The electromechanical power steering is available with the optional Power steering Plus function. It provides steering assistance between 0 and 30 mph (0 and 50 km/h) for enhanced comfort, particularly while parking and manoeuvering thanks to less steering effort being required. The steering torque, the active return (automatic reset to steering wheel center position) and the steering damping are adapted according to the driving situation, e.g. at low speeds.

Steering wheel adjustment Like the previous models, the new 911 Carrera models feature the sports steering wheel including mechanical steering column adjustment as standard. The

10 mm. This enhances operating comfort and driver’s seat ergonomics for sporty driving.

4_21_11

The steering wheel can be adjusted electrically in conjunction with the fully electric sports seats (14 way) and the Adaptive Sports seats Plus (18 way).

4_20_11

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adjustment travel for steering wheel reach adjustment has been increased by

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911 Carrera 911 Carrera S

4.5 Dynamic engine mountings To further improve the driving dynamics as well as driving and vibration comfort, the Sport Chrono package on the new 911 Carrera models now also comes with dynamic engine mountings (Porsche Active Drivetrain Mount, PADM) as were previously only used on the 911 Turbo and 911 GT3 models.

Chassis

4

These adjust their rigidity and damping depending on the driving situation. They significantly minimize the transmission of vibrations in the entire drivetrain and in

1_20_11

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particular from the engine to the body.

The delayed power impulse produced by the mass moment of inertia of the engine when steering into a corner or during a quick series of alternating bends, for example, is significantly reduced and any pushing from the rear minimized. Inspired by racing cars, in which the drive unit is bolted rigidly to the body, this leads to more stable and precise handling. The disadvantages are noticeable engine

1_22_11

vibrations and reduced day-to-day usability for a comfort-orientated driving style.

This vibration is filtered by way of softer mounts.

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4

time reduce vertical engine vibration during acceleration at full throttle. The result is more uniform and higher drive power at the rear axle with higher traction and better acceleration. The system is automatically controlled by the PASM control unit or a separate control unit* with a highly dynamic control loop and response times of just a few milliseconds when switching between soft and hard engine mountings.

! *The control unit is housed behind the

A large amount of information is processed, including the steering angle, lateral,

rear seat assembly. It is programmed as

longitudinal and vertical acceleration as well as the fluid pressure in the respective

PASM and PADM, as PASM only or as

engine mounting. The control strategy of the dynamic engine mountings is also

PADM only depending on the equipment

influenced by the sport functions pre-setting. Depending on whether the SPORT or

version.

SPORT PLUS button is activated, the pre-set damping of the engine mountings is decreased or increased as required for sporty driving. In the sportiest setting SPORT PLUS, for example, a control strategy suitable for race circuits with greater rigidity of the engine mountings is pre-selected.

Function The dynamic engine mountings comprise an electric coil and two chambers filled with magnetizable (magnetorheological) fluid. The upper chamber is coupled to the body, while the lower chamber is connected to the drive unit. The chambers are connected to each other by means of an annular gap. The electric coil is located directly next to this annular gap. Relative motion between the engine and the body forces the fluid through the annular gap. An electromagnetic field is generated in this annular gap by means of a defined electric current through the coil. This modifies the viscosity of the magnetorheological fluid and the engine mountings are made softer or harder. When there is no current flowing through the coil, the fluid has a relatively low viscosity and the flow resistance is low. The mountings have low 1_21_11

rigidity and damping and are therefore soft. When a defined current is applied to the coil, the iron particles in powder form in the fluid are magnetized and join together to create chains. The fluid becomes viscous and the flow resistance high. The mountings are then characterized by high rigidity and damping and are therefore hard.

1_23_11

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Chassis

The dynamic engine mountings combine both of these advantages and at the same

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911 Carrera 911 Carrera S

The system is controlled by a separate control unit with a highly dynamic control loop and response times of just a few milliseconds when switching between soft and hard engine mountings. A large amount of information is processed, including

Chassis

the steering angle, lateral, longitudinal and vertical acceleration as well as the fluid pressure in the respective engine mounting. To ensure excellent driving dynamics

4

and functionality, vehicles with dynamic unit mountings feature separate and independent control of the right and left engine mountings. The control strategy of the dynamic engine mountings is also influenced by the PSM vehicle stability system pre-setting and other driving conditions described later on.

Overview The inputs and outputs of the control units as well as the corresponding signals are

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shown below.

Gateway

Chassis CAN Lateral acceleration Longitudinal acceleration Vehicle speed Wheel speed, FR/FL/RR/RL

Error message on

Engine torque

instrument cluster

Clutch switch PDK shifting Steering angle Steering angle change time Engine speed Accelerator-pedal position

PADM control unit

Sport button

Left mounting Control current Sensor signal

Driver request torque

!

Legend:

Transmission status

Chassis CAN Display CAN Right mounting

PWM signal

Body acceleration sensor,

Control current

Analog signal

front right

Sensor signal

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4.6 Porsche Active Suspension Management General Porsche Active Suspension Management (PASM) has been revised and enhanced on the new 911 Carrera models (991). In contrast to the previous models, there are four additional height sensors on the front and rear axle and another front left body acceleration sensor for even more precise control. The result is significantly enhanced comfort in both programs.

PASM is a shock absorber system for active and continuous damper control at the front and rear axle and is used as standard in the 911 Carrera S. It regulates the damping force for each wheel individually, depending on driving style and driving

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conditions.

4_29_11

4_28_11

Design and function Body acceleration sensors Uneven road surfaces act on the chassis via the wheels and cause vertical movements and vertical accelerations of the vehicle body. By actions such as 4_30_11

steering, acceleration and braking etc., the driver also produces pitch, roll and/or yaw reactions of the vehicle. The body acceleration sensors detect the body movements and transmit them to the control unit. For optimum detection of these movements, two of the sensors are attached to the suspension strut domes on the right and left (Fig. 4_29_11). A third sensor is mounted at the rear left close to the suspension strut mount (Fig. 4_30_11).

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The height sensors are used in addition to the body acceleration sensors for detecting and evaluating rolling and pitching movements. The road conditions are also determined according to the angular velocity and transmitted to the control unit.

4_31_11

Control unit The signals from the body acceleration sensors and height sensors as well as information about lateral acceleration, steering angle, brake pressure, engine torque and vehicle speed are supplied to the control electronics. Based on this data, the required damping force for each wheel is calculated individually in just a

Chassis

4 cardiagn.com

Height sensors

few milliseconds and individual damper control is initiated. As a result, only the actually required damping forces are set in all driving situations, thereby reducing body movements.

The driver is able to choose between the Normal and Sport programs via the PASM chassis button in the center console. In vehicles equipped with the optional Sport Chrono package, an even sportier set-up for the PASM chassis can be selected using the SPORT PLUS button. Depending on the mode and the current road and driving conditions, PASM individually regulates the optimum damping force for each wheel as required. The required damping force is always calculated and applied for each wheel in both programs, as described above. PASM is controlled by regulating the fluid flow in the dampers. In Comfort mode, for example, the fluid can flow freely and damper control is comfort-oriented.

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911 Carrera 911 Carrera S

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4

Depending on the selected mode, the flow paths close or are narrowed and the fluid is prevented from flowing through. This principle allows the damping force and vehicle handling to be controlled continuously or at the push of a button.

Level sensor, front left

Gateway

Level sensor, front right Level sensor, rear left Instrument cluster:

Level sensor, rear right

Body acceleration sensor, front left/right

PASM button

Body acceleration sensor, rear

Sport/Sport Plus button

left

PASM/PADM control unit FR damper valve FL damper valve

Drive CAN:

RR damper valve

Speed

RL damper valve

Lateral acceleration Yaw speed

Sensor power supply

Steering angle Brake status Engine torque

Engine bearing right/left

Engine speed

control current sensor signaly

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Text/Symbols

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911 Carrera 911 Carrera S

4.7 Porsche Dynamic Chassis Control General The active chassis control system, Porsche Dynamic Chassis Control (PDCC), is optionally available for the new 911 Carrera S models. PDCC is an active chassis system for roll compensation which senses and fully compensates for the lateral

Chassis

4

inclination of the vehicle during cornering. The system enables increased agility at all speeds, improved steering behavior and balanced load alteration behavior. PDCC also offers enhanced driving comfort (particularly when driving straight ahead on uneven road surfaces) thanks to extensive decoupling of the anti-roll bars, resulting in fewer copy effects. Driving safety during fast lane changes is also increased thanks to the suppression of body movements and almost total compensation of the

when combined with the Sport Chrono package thanks to the SPORT PLUS button.

PDCC is therefore not only a new highlight with respect to driving dynamics, but also improves comfort in certain driving situations.

Compared with the PDCC with variable pivot motor and split anti-roll bar used in the Cayenne and Panamera models, a newly developed system with actively adjustable hydraulic cylinders is used here, which takes into account the space restrictions in sports cars.

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roll angle. PDCC is always active and offers further enhancement of performance

4_32_11

Vehicles equipped with the Porsche Dynamic Chassis Control option have the “PDCC” logo on the center console.

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Design/components The variable anti-roll bar system, PDCC, consists of the components shown in Figure 4_33_11 on the front and rear axle.

1 Controlled hydraulic pump with reservoir 2 Active hydraulic cylinders, rear axle 3 Rear-axle valve block with flow separator 5 Front-axle valve block 6 Anti-roll bars 7 Cooler

4_33_11

Hydraulics diagram 1 Intake restrictor 2 Hydraulic pump 3 Rear-axle valve block 4 Flow separator 5 Pressure-regulating valve 6 Direction valve 7 Pressure sensor 8 Hydraulic cylinder, rear right 9 Hydraulic cylinder, rear left 10 Hydraulic cylinder, front right 11 Hydraulic cylinder, front left 12 Failsafe valve 13 Front-axle valve block 14 Heat exchanger 15 Filter (in reservoir) 4_40_11

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4 Active hydraulic cylinders, front axle

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911 Carrera 911 Carrera S

Operating principle The variable anti-roll bar system resolves the conflict between the objectives of a minimal tendency to roll in dynamic driving situations (sportiness) and extensive decoupling of the anti-roll bar when driving straight ahead and on occasionally uneven road surfaces (comfort).

Chassis

4

The PDCC improves driving performance by increasing the tire contact surface in dynamic driving situations (camber optimization for tires). The lateral inclination of the vehicle, e.g. when steering into a bend, when cornering and during fast lane changes, is significantly reduced and allows almost complete prevention of vehicle inclination up to maximum lateral acceleration depending on the driving situation.

cylinders of the front and rear axle are activated at the left side of the vehicle in order to compensate for the tendency to roll. This compensation increases the tire contact surface and therefore allows increased transmission of lateral forces.

Thanks to differentiated control on the front and rear axle, the system also offers variable distribution of the bearing forces between the front and rear axle and therefore variability of the tire contact surfaces.

The variable anti-roll bar system, PDCC, facilitates these driving characteristics with electronically controlled, variable filling of the upper and lower chambers of the hydraulic cylinders with fluid. This modifies the travel of the cylinder and pretensioning of the respective anti-roll bar is increased or reduced. The variable filling of the chambers is achieved through the opening and closing of hydraulic control valves in the valve blocks on the front and rear axle. There are no separate

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This means that when steering into a right-hand bend, the adjustable hydraulic

controls for PDCC. When PASM shock absorber tuning is selected, PDCC activates the relevant control program automatically.

Hydraulic pump with reservoir The hydraulic system features an adjustable hydraulic pump, control valves and supply lines for supplying the hydraulic cylinders. The hydraulic pump is driven by the motor via the belt drive. To minimize fuel consumption, the pump capacity and delivery rate are continuously regulated and adapted via an intake restrictor (1). As a result, the volume flow remains constant despite the variable pump speed (engine speed) and only the quantity of fluid actually required is drawn in. The reservoir is mounted directly on the pump. A filter, which filters the fluid flowing back in, is integrated in the reservoir. A dipstick is fitted to the cap for checking the fluid level.

4_35_11

Note: The filter needs to be changed every 60,000 miles (90,000 km) or 6 years.

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The fluid that flows back is routed via the fluid-water heat exchanger for cooling (arrow in Fig. 4_36_11).

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4

Chassis

Cooling

Valve blocks for front and rear axle 4_34_11

1 Reservoir 2 Radial piston pump

4_36_11

Supply lines lead from the pump to the individual hydraulic cylinders via hydraulic control valves. The control valves for the anti-roll bar on the front and rear axle respectively are housed in two separate valve blocks.

The valve block for the rear axle (Fig. 4_37_11) comprises the pressure sensors, a pressure-regulating valve and the direction valve. The flow separator that distributes the volume flow delivered from the pump to the front and rear axle is located inside 4_37_11

1

Pressure-regulating valve

2

Direction valve

3 and 4 Pressure sensors

136

the valve housing.

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911 Carrera 911 Carrera S

The valve block for the front axle comprises the pressure sensors (1), the pressure-regulating valve (4), the direction valve (3) and the failsafe valve (2).

Chassis

4

1 Pressure sensors 2 Failsafe valve 3 Direction valve

4_38_11

Hydraulic cylinder The variable hydraulic cylinders are located between the anti-roll bar and the suspension strut and replace the rigid “connecting links”. The lower section of the hydraulic cylinder is connected to the outer bolting points of the anti-roll bars and the upper section is connected to the respective wheel carrier. The maximum adjustment travel is 70 mm.

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4 Pressure-regulating valve

Control unit The control unit is mounted at the front left in the luggage compartment under the 4_39_11

side member.

4_54_11

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911 Carrera 911 Carrera S

Chassis

4

The control unit has direct access to the current hydraulic cylinder pressures via the pressure sensors and to the body and acceleration sensors. The control unit receives all other information for controlling the system, such as steering wheel angle, vehicle speed, lateral and body acceleration, yaw rate and compression travel, via the vehicle-internal CAN data bus. The control unit activates the valves in the valve blocks of the front and rear axle in the same way.

Level sensor, front left

Gateway

Level sensor, front right

Instrument cluster:

Level sensor, rear right

Text

Body acceleration sensor, front left/right

Rear-axle valve block

Body acceleration sensor,

Direction valve

rear left

Pressure-regulating valve Pressure sensor 1 PDCC control unit

Pressure sensor 2

PASM button Front-axle valve block Direction valve Drive CAN:

Pressure-regulating valve

Speed

Failsafe valve

Lateral acceleration

Pressure sensor 1

Yaw speed

Pressure sensor 2

Steering angle Engine speed

PDCC pump

Nominal engine idle speed

Intake throttle valve

Outside temperature

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Level sensor, rear left

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911 Carrera 911 Carrera S

Diagnosis In addition to on-board diagnosis by the control units and checks on sensors and valves, the pressure that exists in the system is continuously monitored. Depending on the engine speed, the calculated nominal pressure values are compared with the current actual pressure values detected by the four pressure sensors. If a fault is

Chassis

4

detected, PDCC switches to failsafe mode. If a fault occurs during PDCC operation, the driver is alerted to this by the message “PDCC fault” on the on-board computer.

Failsafe mode In the event of a major fault, the entire system is switched to failsafe mode in order to maintain safe driving conditions. The failsafe valve (see Fig. 4_41_11, no. 12) in

the pump hydraulic system to short-circuit. The hydraulic fluid from the pump flows directly back into the reservoir. At the same time, the connections for the hydraulic cylinders (see Fig. 4_41_11, no. 10/11) are closed so that the pressure in the cylinders is maintained. The anti-roll bar remains in this position and continues to operate in the conventional manner.

The hydraulic circuit at the rear axle is completely depressurized so that the hydraulic cylinders are decoupled. This increases the vehicle’s lateral inclination during cornering. The vehicle responds by understeering slightly, but can be driven at an appropriate speed to the nearest authorized Porsche dealer.

VL

A

B

VR

B

A

A2

U

A1

B1

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the front-axle valve block (see Fig. 4_41_11, no. 13) is de-energized, which causes

B2

U p

p

P

T 4_41_11

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Chassis

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4.8 Wheels and tires The new 911 Carrera models feature newly developed 19-inch and 20-inch wheels.

The flow forming* production technology used contributes to reducing weight and therefore also improves driving comfort by reducing the unsprung masses. The 911 Carrera basic models are equipped with 19-inch Carrera wheels as standard. The 911 Carrera S models come with the new 20-inch Carrera S wheels as standard.

* With flow forming, the rim base of the wheel blank is rolled via a cylinder in a

Overview of wheel and tire dimensions Front axle

Rear axle

911 Carrera

8,5 J x 19 ET 54; 235/40 ZR 19

11 J x 19 ET 63; 285/35 ZR 19

911 Carrera S

8,5 J x 20 ET 51; 245/35 ZR 20

11 J x 20 ET 70; 295/30 ZR 20

formed and compressed. This results in rims with thin wall thicknesses that offer maximum stability along with minimum weight and use of materials.

For the new 911 Carrera models, the new tire generation from all manufacturers has been optimized with regard to rolling resistance in particular, while still guaranteeing the performance typical for Porsche with respect to handling and braking distance as well as weight.

Tires generally offer a high potential for reducing fuel consumption. The three basic components for optimization are the rubber compound, the tread design and the casing architecture. By reducing the rolling resistance (-7% compared with previous models), it has been possible to achieve a reduction in fuel consumption. Increasing the rolling circumference on the front and rear axle by 4% compared with previous 19-inch Carrera wheel

4_54_11

models has significantly improved handling and comfort. The 20-inch tires are designed especially for performance and sporty driving. Thanks to their special rubber compound and low tire cross-section, they offer performance advantages for fast cornering.

Comfort pressure For vehicles equipped with TPM, the tire pressures can be reduced to improve comfort. Tire Pressure Monitoring must be adjusted to the tire pressure used (comfort pressure or standard pressure). E.g. if “Comfort press” is selected, TPM automatically uses low required pressures for monitoring the tire pressure and a country-specific speed warning is activated.

20-inch Carrera S wheel

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single step. The material is therefore

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911 Carrera 911 Carrera S

Tire repair systems Like the previous models, the new 911 Carrera (991) models come as standard with a space-saving tire repair system comprising tire sealing compound and an

Chassis

electric pneumatic compressor.

4

4.9 Tire pressure monitoring Timely detection of a gradual loss of pressure increases driving safety. It can also prevent uneven tire wear and increased fuel consumption due to inadequate tire pressure. The correct tire pressure additionally supports safe driving and high driving dynamics.

Tire Pressure Monitoring (TPM Generation 2.6) continuously monitors the tire

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pressure separately for all four wheels. Compared with the TPM Generation 2.3, which was installed in the Carrera as from model year 2009, the antenna is now integrated in the control unit in the new TPM Generation 2.6. The basic functions have not changed.

Structure The system comprises the following components:

1 TPM control unit with integrated antenna 2 Trigger transmitters 3 Wheel electronics

4_42_11

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Chassis

4

Control unit The TPM control unit with integrated antenna is mounted on the outside in the underbody area on the coolant lines. The control unit is water-tight. The underbody panelling serves as additional protection for the control unit. The location of the control unit on the outside of the vehicle ensures that wheel electronics reception is not subject to interference as a result of various conditions in the passenger or luggage compartment or due to metallized heat-insulating glass. The control unit is available in the country-dependent frequency variants 433 MHz and 315 MHz.

Instrument cluster

Terminal 31 Terminal 15

CAN:

TPM control unit

Speed

433/315 MHz

Front left trigger

Wheel electronics

Front right trigger

Wheel electronics 125 kHz

Outside temperature Engine speed

Rear left trigger

Wheel electronics

Rear right trigger

Wheel electronics

433/315 MHz Integrated antenna

Speed warning for comfort pressure A lowered comfort air pressure can be used for increased driving comfort up to a maximum speed of 165 mph (270 km/h) or 100 mph (160 km/h) for so-called “low-speed countries”. This is also monitored by TPM.

If the maximum speed for the set comfort pressure is exceeded and the tire pressure falls below a critical value, the warning “Comfort pressure Reduce speed” appears in the multi-function display.

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Terminal 30

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911 Carrera 911 Carrera S

4.10 Brake system General All 911 Carrera models feature a 8’’/9’’ tandem brake booster in a lightweight aluminum design in order to adapt the braking performance to the enhanced driving performance and to ensure best-in-class braking performance. The proven standard

Chassis

4

brake system from the previous models is used in the 911 Carrera. 6-piston aluminum monobloc fixed-caliper brakes and integral-type brake discs with a diameter of 340 mm are used on the front of the 911 Carrera S. At the rear, all models are braked by 4-piston aluminum monobloc fixed-caliper brakes and brake discs with a diameter of 330 mm.

4_43_11

Model

4_44_11

911 Carrera

911 Carrera S

Calipers

FA RA Color

4-piston monobloc 4-piston monobloc Black

6-piston monobloc 4-piston monobloc Red

Discs

FA RA

330 x 28 mm 330 x 28 mm Cross-drilled and internally vented

340 x 34 mm 330 x 28 mm Cross-drilled and internally vented

8’’/9’’ tandem

8’’/9’’ tandem

Brake booster

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Overview

Porsche Ceramic Composite Brake The new 911 Carrera models are also optionally available with the proven Porsche Ceramic Composite Brake (PCCB) with ceramic brake discs and 6-piston monobloc fixed calipers on the front axle. The dimensions have been adopted from the previous models. The PCCB offers familiar advantages over a brake system that uses steel discs of comparable design and size. As in previous models, the brake

4_45_11

calipers of the PCCB are yellow and are therefore easily distinguished from the standard brake systems.

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Chassis

4

4.11 Electric parking brake General All 911 Carrera models feature an electrically operated parking brake (EPB) for the first time, which can be controlled conveniently by way of a button at the left of the steering wheel. The electric parking brake can be activated manually using this switch and deactivated when the footbrake is pressed. It is also released automatically following manual activation when the driver’s intention to drive off is detected via the accelerator pedal. The electric parking brake therefore increases comfort and safety when the vehicle is parked and creates more space in the center console due to the omission of the handbrake lever.

Activating when the vehicle is stationary Conditions: • Vehicle speed less than 1.4 mph (2.2 km/h) • At least one valid wheel signal per axle 4_46_11

• Press operating control

Emergency operation If there is not at least one valid wheel signal available on each axle, the electric parking brake can be applied and the vehicle reliably held under the following conditions: • Ignition off • Operating control pressed for longer than 10 seconds

Releasing when the vehicle is stationary Conditions: • Ignition on • Brake pedal pressed • Pull operating control

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Functions

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911 Carrera 911 Carrera S

Automatic release when driver’s intention to drive off is detected The electric parking brake is released automatically on the flat (gradient of less than 5°) when the driver’s intention to drive off is detected. On a gradient of more than 5°, release of the parking brake depends on the downgrade force.

Conditions:

Chassis

4

• Engine running • Gear selected (PDK = selector lever in D or R, manual transmission = clutch pressed) • Accelerator pedal pressed • Driver’s seat belt fastened

Emergency braking In dangerous situations, it is possible to decelerate very sharply and stop the vehicle using the electric parking brake instead of the footbrake. Vehicle deceleration of 0.8 g is achieved in this case.

Conditions: • Vehicle speed above 2.2 mph (3.5 km/h) • One valid wheel signal per axle • Press operating control continuously

Special functions Brake test stand mode The braking action of the parking brake can be tested at any time on a roller-type test stand. The system automatically switches to test mode as soon as one axle is driven while the other is stationary. The service brakes of the front and rear axle

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• Driver’s door closed

can be tested normally. To test the parking brake, the button must be pressed continuously until the highest braking torque is reached or the vehicle jumps out of the test stand.

Emergency release The emergency release function should be used only if the brake can no longer be released electrically (actuating element itself is faulty). The oval-head screw on the back must be removed and the brake released using an Allen key for this purpose.

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4

Chassis

Control unit The control unit is mounted on the control unit carrier behind the rear seats.

PSM control unit (CAN)

Instrument cluster

Speed

Texts, function light

Longitudinal acceleration Brake light sensor

Parking brake switch

Emergency braking

Function light

Left actuator PSM unit

Servo motor

Pump motor

Hall-effect sensor

Inlet valve FL

EPB

Inlet valve FR

control unit

Right actuator

Inlet valve RL

Servo motor

Inlet valve RR

Hall-effect sensor

Operating control button

PDK Gear selected Terminal 15, 30, 31 Clutch sensor (manual transmission only)

The EPB control unit receives input signals from the PSM control unit: Speed signal (CAN) - wheel speeds are detected in order to run the various functions, depending on vehicle speed.

Longitudinal acceleration (CAN) - the gradient is detected in order to activate/deactivate the Drive-Off Assistant.

Brake light sensor (CAN) - instead of a conventional brake light switch, a Hall-effect sensor (see Fig. 4_47_11) transmits the position of the brake pedal. It consists of two Hall-effect sensors with a permanent magnet mounted in front.

4_47_11

146

If the pedal touches the sensor when released, the position is detected by the

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(brake pressure build-up)

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911 Carrera 911 Carrera S

change in the magnetic field. If the system detects that the brake is pressed, the parking brake is released on request.

Chassis The EPB control unit supplies information regarding the targeted build-up of brake pressure required for the introduction of emergency braking to the PSM control unit.

4

Clutch sensor (manual transmission only) The clutch sensor, which is located on the clutch master cylinder, supplies another input signal in order to detect the position of the master piston. The piston contains a permanent magnet for this purpose. The different positions of the magnet generate particular field strengths, which can be used to determine the sensor

tion about the position of the piston such as clutch pedal pressed, piston travel and clutch fully depressed.

• The first signal switches off adaptive cruise control.

• The next signal is a pulse-width-modulated signal, which indicates the piston travel. This is used in conjunction with the Drive-Off Assistant to slowly reduce the brake pressure as a function of clutch travel.

• The third signal, with the clutch pedal fully depressed, is the switching position for the Start Lock function (Interlock).

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position. The sensor supplies up to three different signals, which provide informa-

4_48_11

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4

4.12 Porsche Stability Management General Generation 9.0 of the standard enhanced Porsche Stability Management (PSM) ensures superior active driving safety even in the longitudinal and lateral dynamic limit range while still maintaining typical Porsche agility. For the new 911 Carrera (991) models, the PSM set-up was modified and adapted, e.g. to use of the new Porsche Torque Vectoring/Plus (PTV/PTV Plus). Sensors continuously monitor the direction of travel, vehicle speed, yaw velocity and lateral acceleration of the vehicle. Using this information, PSM calculates the actual direction of movement. If the car begins to oversteer or understeer, e.g. PSM initiates selective braking on individual wheels to restore stability. PSM improves active safety through the

• ABS (Anti-lock Brake System) • EDTC (Engine Drag Torque Control) • ASR (Anti Slip Regulation) • ABD (Automatic Brake Differential) • EBD (Electronic Brake-force Distribution) • Enhanced braking readiness through pre-filling of the brake system • Brake assist function: generates the brake pressure needed for maximum deceleration when emergency braking is detected • Standstill management: Auto-hold function in conjunction with the electric parking brake • Driving dynamics control: wheel-specific braking intervention to ensure driving stability

The new standstill management function (Auto-hold function) prevents the vehicle from rolling back in the opposite direction to the desired driving direction. If the vehicle is braked to a stop on a gradient, the Auto-hold function is active and the required brake pressure is maintained via PSM. On vehicles with PDK, the Auto-hold function also holds the vehicle if the driver allows the vehicle to coast to a stop on a gradient. As soon as the vehicle comes to a stop without braking, the brake pressure is maintained via PSM for holding the vehicle on the gradient until it moves off again. The hold function is transferred to the electric parking brake after 5 minutes or if the system detects that the driver intends to leave the vehicle.

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following functions/systems:

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911 Carrera 911 Carrera S

The detected enhanced braking readiness through pre-filling of the brake system serves to shorten the stopping distance in emergencies. When the accelerator pedal is released quickly, PSM places the brake system in a state of enhanced

Chassis

braking readiness: pre-filling of the brake system builds up a slight pressure in the system. The brake pads are therefore already in light contact with the brake discs.

4

If the driver then actually presses the brake, maximum braking power can be achieved more quickly and this results in a shorter stopping distance.

When emergency braking is identified – i.e. when the driver very quickly removes his foot from the accelerator and presses the brake pedal with a defined minimum pedal force - brake assist generates the brake pressure needed for maximum

Depending on the vehicle equipment with other chassis control systems such as PASM and PDCC, PSM uses the sensor information provided by these chassis systems to optimally match the sub-functions of PSM control with the behavior of the other control systems. PASM supplies information about road contact forces and uneven road surfaces. This information is read in by PSM and is used for optimal, situation-based adaptation of ABS control in order to optimize the braking distance in emergency braking situations, even with different road conditions.

PSM diagram

1 Control unit

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deceleration via the PSM hydraulic unit.

2 Hydraulic unit 3 Sensor cluster 4 Speed sensor P

U

5 Steering-angle sensor 6 Vacuum sensor 7 Brake light sensor

P/U

8 PSM OFF button CAN

DME

EPB

9 Instrument cluster 10 Parking brake switch

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4

Components Hydraulic unit The hydraulic unit is installed close to the plenum panel/wheel housing on the front left. The dual-circuit brake system is divided up between the front and rear axles (black/white distribution). The connections have different thread diameters in order to prevent the lines from being interchanged (see Fig. 4_50_11).

Brake light sensor Instead of a conventional brake light switch, a brake light sensor (see Fig. 4_47_11) transmits the position of the brake pedal. The brake light sensor has two Hall-effect sensors and a permanent magnet and is adjustably mounted directly on the brake

changes; this signal is in turn evaluated in the DME control unit as a brake signal and supplied to PSM via CAN (gateway).

4_50_11

Steering-angle sensor The steering-angle sensor consists of an optical segment sender and a code disc as well as a sensor lever that meshes with a spiral on the back of the code disc.

The light emitted by the segment sender is interrupted by the coding in a specific sequence from which the system can calculate the exact steering angle within 360°. The lever that meshes with the spiral can detect the full revolutions. The current position of two revolutions to the left or right can be detected in the control unit by evaluating these two pieces of information.

4_47_11

The data determined in the integrated microprocessor is sent to the PSM control unit via the CAN bus.

4_51_11

!

In contrast to earlier systems, calibration of the steering-angle sensor is no longer controlled via PSM, as it has a separate diagnostic interface (steering column module).

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pedal. When the brake pedal is pressed, the signal from the Hall-effect sensors

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911 Carrera 911 Carrera S

Vacuum sensor

4

A vacuum sensor is installed between the vacuum pump and brake booster. The Auto Start Stop function is deactivated if the vacuum in the brake booster is

Chassis

insufficient. The engine is switched off if the requirements for the Auto Start Stop function are met by the vacuum present in the brake booster. The engine is started again if the vacuum drops below a certain value (e.g. the driver moves the brake pedal).

2

Speed sensor The installed speed sensors DF11i are designated as “active speed sensors” that work on the Hall-effect principle and detect both forward and reverse motion. The

1

speed sensors provide the PSM control unit with data on the wheel speed and

supply. The connection with the control unit is established via two-cable wiring. The

1 Vacuum sensor

active speed sensor is provided with power and ground by the PSM control unit. The

2 Vacuum brake booster

function of the sensor element integrated into the active speed sensor is primarily based on the change in ohmic resistance in an electronic system depending on the strength and direction of a magnetic field. The resistance change is transformed into a speed signal and sent to the PSM control unit by an electronic circuit in the sensor element.

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4_52_11

direction of travel at any given time. Active speed sensors require an external power

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4

Chassis

PSM control unit The PSM control unit is part of the hydraulic unit and is permanently mounted to the valve block. The incoming signals are processed inside the control unit and forwarded directly to the integrated valves and to the relays (drivers).

Terminals 15, 30 and 31

ACC

Speed sensor FL, FR, RL, RR

Brake request

Vacuum sensor Airbag Sensor cluster

Driver’s door open/closed

Combined steering column module Steering angle

PASM

Gateway

Level Body acceleration

PSM control unit Instrument cluster

EPB

Texts, function and warning

Emergency braking Transfer to EPB (clutch pedal)

lights

Solenoid valves Pump relay

A/C control unit

Valve relay

PSM OFF button, Sport,

PDCC

Sport Plus

Control mode DME Power steering Status

Engine torque

Pressure sensor

Engine speed Accelerator pedal position Brake light switch Auto Start Stop

PDK Gear information (rear differential lock)

152

PSM internal

longitudinal acceleration

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Driver's belt buckle

Rotation rate, lateral acceleration,

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911 Carrera 911 Carrera S

4.12 Porsche Torque Vectoring The 911 Carrera S is equipped with PTV/PTV Plus as standard. PTV/PTV Plus is offered as an option for the 911 Carrera. PTV includes a mechanical rear differential lock with an asymmetric action (22% traction, 27% deceleration) and is always offered in combination with the standard 7-speed manual transmission. PTV Plus

Chassis

4

includes a fully variable electronic rear differential lock and is always offered in combination with PDK.

Unlike the previous models, in which only one locking differential was offered to additionally support the driving dynamics, Porsche Torque Vectoring/Plus (PTV/PTV

4_53_11

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Plus) now provides a much improved product feature for all transmission variants.

PTV/PTV Plus mainly improves the steering behavior and steering precision of the vehicle when driving very dynamically by selectively braking the rear right or rear left wheel. PTV/PTV Plus offers distinct advantages, particularly when steering into a bend. Selective braking is applied on the inside rear wheel as soon as the steering is turned. This gives the outside rear wheel higher drive torque in comparison with the inside wheel. This difference in torque gives the vehicle a yawing moment that also supports the steering angle of the vehicle. The braking interventions for PTV/PTV Plus are also active when Porsche Stability Management is deactivated (PSM OFF). With regard to agility and steering precision, the active braking interventions offer advantages at low and mid-range speeds (up to approx.

100 mph/160 km/h). At higher speeds, PTV/PTV Plus and the rear differential lock offer additional driving stability, in addition to advantages of driving dynamics.

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911 Carrera 911 Carrera S

5 Body

5.1 General The following objectives were pursued in the development of the body of the new 911 Carrera (991) models to further enhance the visual attractiveness, safety and

Body

performance of the vehicles: • Exciting, sporty and typical 911 design

5

• More space in the passenger compartment

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• Significant weight reduction

General

155

Unpainted bodyshell

157

Aerodynamics

162

Slide/tilt roof

165

Exterior mirrors

166

Roof transport system

166

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911 Carrera 911 Carrera S

Body

5

The objectives that were implemented in the vehicle are listed in the table below.

Development objective

Implementation

Significant weight reduction for improved driving performance and reduced fuel consumption

Intelligent lightweight construction with multi-material design

Higher torsional rigidity for improved

Weight saving of up to 88 lbs (40 kg)

driving performance 25% higher torsional rigidity Passive pedestrian protection system

requirements, including pedestrian protection Improved aerodynamics for enhanced

Lower lift coefficients

driving performance

cAF, cAR = -0.01

New sliding roof concept with larger opening area and no headroom

New external slide/tilt roof

restrictions

The new 911 Carrera models have a completely redesigned body in an aluminum/steel composite design. The idea behind this intelligent lightweight construction concept is use of “the right material in the right place”. This means: • Extensive use of aluminum to reduce the vehicle weight • Use of ultra-high-strength steel for greater body rigidity and optimum passenger safety

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Compliance with current safety

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911 Carrera 911 Carrera S

A more detailed look at the body of the new 911 Carrera models reveals the following mix of materials:

Body Material

Components

5

Luggage compartment and fenders Aluminum

Doors, roof, engine compartment lid Front section, center floor and rear end

Front & rear roof cross members Steel Reinforcements in the doors & sill panels Body front section & rear-end reinforcements

The following highlights of the new body are described below: •

Unpainted bodyshell (Section 5.2)

•

Aerodynamics (Section 5.3)

5.2 Unpainted bodyshell Weight distribution Nearly half of the entire body weight is made from aluminum, which has been a significant contributing factor in reducing the vehicle weight. The illustration below

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Rear side sections & sidewall structure

shows which components are made from which materials.

Weight proportion of unpainted bodyshell

5_02_11

44.6 % aluminum 55.4 % steel

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5

illustrations below show the respective weight proportions of these individual components.

Weight proportion of add-on parts

5_03_11

93.1 % aluminum 6.9 % steel

Weight proportion of main bodyshell

5_04_11

36.2 % aluminum 63.8 % steel

Altogether, the measures have enabled a net weight reduction of around 209 lbs (95 kg) with regard to the body compared with the previous models. The use of aluminum doors alone has achieved a weight saving of around 31 lbs (14 kg).

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Body

The unpainted bodyshell consists of the main bodyshell and add-on parts. The

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911 Carrera 911 Carrera S

Aluminum body components (front section, center floor and rear end), other cast aluminum parts and extruded

Body

aluminum profiles are used in specific areas.

Aluminum sheet Cast aluminum 5_05_11

Extruded aluminum profile Sheet steel

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5

In addition to extensive use of sheet aluminum parts in the platform assemblies

5_06_11

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Body

5

Body properties In addition to a very good power-to-weight ratio, the rigidity of the body makes a significant contribution to driving performance. However, increased rigidity normally means additional weight, which conflicts with the objective of reducing weight. This conflict of objectives has been resolved by an intelligent lightweight construction with multi-material design:

• Torsional rigidity increased by 25% • Intrinsic torsional frequency increased by 20% • Intrinsic flexural frequency by 13%

The consistent further development of the lightweight body also makes a significant contribution to safety. In the event of a crash, the forces that occur are distributed to longitudinal and cross member structures in the body front section and rear end in a predefined manner. The ultra-high-strength steels used ensure high strength, and in the event of an impact, optimum energy dissipation. They surround the passenger cell like a cage and with their extreme dimensional stability play an important role in maintaining the integrity of the cabin and therefore protecting the occupants. The optimized deformation behavior of the aluminum luggage compartment lid and the fender as well as the composite aluminum and steel hinges meet the objectives for intelligent lightweight construction while at the same time satisfying ever-increasing global requirements with respect to pedestrian protection. This passive safety system also meets the weight requirements of the 911 Carrera models thanks to the use of state-of-the-art materials and design methods.

Cockpit support beam Lightweight construction is also used for the passenger compartment. The cockpit support beam and center console structure are made of die-cast magnesium.

This not only reduces the vehicle weight by a further 3.74 lbs (1.7 kg) but also significantly improves the vibration behavior - so-called steering wheel shake.

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• Weight of bodyshell structure reduced by 13%

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911 Carrera 911 Carrera S

Steel body components

5

Another challenge during the development of the body of the new 911 Carrera models was connecting the floorpan assembly, which is made from aluminum

Body

components wherever possible, to the steel assemblies of the body structure. In addition to self-piercing rivets, clinch and flow-drill joints, bonded joints are used extensively. The advantage of bonded joints lies the application of force over the entire surface. This increases the strength of the joins. On other parts of the body, adhesive is used for the purpose of sealing, electrochemical insulation and noise reduction.

Further developments in steel processing techniques have allowed the use of ultra-high-strength and extremely thin-walled steels that are tailored to the relevant

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functional requirements in the body. They ensure very high rigidity values and safety while at same time achieving the maximum possible reduction in use of materials.

Deep-drawn steel (soft grade) High-strength steel (microalloyed steel) Higher-strength steel (multi-phase steels) Ultra-high-strength steel (heat-formed, boron-alloyed)

5_08_11

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Body

5

5.3 Aerodynamics General The 911 Carrera (991) models offer significantly improved aerodynamics in comparison with their predecessors. The lift coefficients have been significantly reduced by the new rear spoiler and by detail modifications to the front apron.

In combination with the optional PASM sports chassis (-20 mm), this even achieves

5_09_11

162

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downforce on the rear axle for the very first time.

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911 Carrera 911 Carrera S

Technical data for aerodynamics

Model

997 II

991

Delta

997 II S

991 S

Delta

Drag coefficient cd

0.29

0.29

+/- 0

0.30

0.29

-0.01

Cross-sectional area A [m2]

2.01

2.01

+/- 0

2.01

2.00

-0.01

Drag cd x A [m2]

0.580

0.580

+/- 0

0.603

0.580

-0.023

Front-axle lift cAF

0.05

0.04

-0.01

0.05

0.04

-0.01

Rear-axle lift cAR

0.02

0.01

-0.01

0.02

0.01

-0.01

Total lift cA cA = cAF + cAR

0.07

0.05

-0.02

0.07

0.05

-0.03

Front-axle lift cAF

0.05

0.02

-0.03

0.05

0.02

-0.02

Rear-axle lift cAR

0.02

-0.02

-0.04

0.02

-0.02

-0.04

Total lift cA cA = cAF + cAR

0.07

0.00

-0.07

0.07

0.00

-0.07

Standard chassis/PASM -10 mm

PASM sports chassis -20 mm

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5

Body

Rear spoiler The new aerodynamically optimized rear spoiler is no longer integrated in the engine lid, but is now a completely separate component. If the vehicle is equipped with the tilt/slide roof, the rear spoiler angle differs depending on whether the roof is open or closed. The effective area of the rear spoiler has been increased from 898 mm (997) to 1,137 mm (991) and it extends automatically at 75 mph (120 km/h) and retracts again at 50 mph (80 km/h). Depending on the driving situation and equipment, the rear spoiler extends to two different positions. The vehicle aerodynamics are thus optimally adjusted with respect to drag and rear-axle lift. Further improvement with respect to drag is achieved thanks to guide elements in the outer area of the lower section of the spoiler.

Running along its lower outer edge is the new feature edge, which tapers off into the rear quarter panels and provides an impressive, wide rear view.

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5

spoiler, lower section of the spoiler, bellows, mounting bracket and the spoiler drive with electric drive.

5_10_11

Additional aerodynamic improvements Further aerodynamic improvements were achieved through the following measures: • Improved cooling air routing as a result of optimized air intake and air outlet cross-sections • Improved brake cooling thanks to optimized brake air spoiler • Aerodynamically optimized exterior mirrors • Optimized underbody panelling with smaller cooling openings for the transmission • Improved engine ventilation thanks to the new rear spoiler and new engine compartment lid • Improved air flow behavior at the front wheels as a result of optimized air guide elements • Demand-controlled radiator fan speed reduction in order to reduce drag

5_11_11

164

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Body

The main components of the rear spoiler module are the upper section of the

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911 Carrera 911 Carrera S

5.4 Slide/tilt roof General The new optional slide/tilt roof is available for the first time with an external design in the 911 Carrera models. This means that in contrast to the previous models, on which the sliding roof moved into the body between the outer skin and roof liner, it

Body

5

now opens by sliding over the outer skin. This has two advantages. Firstly, the opening area is increased by approximately 30%. And secondly, there are no headroom restrictions as the roof lining no longer has to be lowered to make room for the slide/tilt roof when this option is selected. The newly developed net-type wind deflector provides optimum wind protection and comfort. It retracts in several stages, depending on the speed. The roof can be opened at speeds up to

5_12_11

5_13_11

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124 mph (200 km/h) and closed up to the top speed.

Emergency closing if the roof drive fails If the roof drive unit is defective, it can be closed manually using the hexagon key from the tool kit.

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Body

5

5.5 Exterior mirrors The exterior mirrors of the new 911 Carrera models have been completely redesigned. They are now flatter with a black housing and, due to the positioning of the mirror base on the door panel instead of in the mirror triangle area as previously, several effects are achieved: • The position and form reflect and repeat the contours of the front body section, creating an integral unit • More delicate design, achieved without restricting visibility to the rear • Visually emphasize the width and the sporty, low design • Reduce wind noise and drag • Reduce the soiling that occurs between the exterior mirrors and side

The electrically retractable exterior mirrors including courtesy lighting are a new 5_15_11

option. This feature enables the mirrors to be folded in and out conveniently at the press of a button in tight parking situations. The integrated courtesy lighting lights up the door area to facilitate getting in and out of the vehicle in the dark.

5_16_11

5.6 Roof transport system As in previous models, a new roof transport system is available as an option for the new 911 Carrera Coupé models. This system comprises two lockable aluminum bars that can be anchored in the lateral roof channels. The roof transport system mounting has been completely redesigned and is integrated under the roof seals in 5_17_11

the bodyshell, where it is not visible from the outside. This has rendered the side roof rails used on the previous models unnecessary and gives the roof area a more harmonious appearance. Eight folding snap-lock brackets are fitted under the seals on the roof rails for mounting the base carrier.

Items can be transported safely with the roof transport system and other add-on modules, e.g. ski rack, bicycle carrier, surfboard holder, roof box or snowboard 5_18_11

holder. The maximum permitted load is 154 lbs (70 kg).

The base carrier used on previous models can no longer be used for the new 911 Carrera Coupé models because of the new integrated mounting.

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windows

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911 Carrera 911 Carrera S

6 Body exterior

6.1 General The exterior of the new 911 Carrera (991) shows a clear differentiation from the previous models while retaining the typical 911 design.

Body exterior

The main changes are: • Enlarged air intakes

6

• New LED front light modules • Compact overhangs • Exterior mirror on door panel • New rear spoiler concept • Narrow LED tail lights • Repositioned reflectors in rear end

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• PORSCHE logo on rear end

6_01_11

General

169

Front and side view

170

Rear view

171

Occupant protection

172

Cupholders

176

Glove compartment

176

Center console storage

177

Luggage compartment lid and engine cover

178

Sun visor

179

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911 Carrera 911 Carrera S

Body exterior

6

6.2 Front and side view Front apron The side air intakes in the front apron were redesigned and enlarged. The front light modules were also redesigned and integrated and now include LED direction indicators, daytime driving and position lights. The front apron is made from the material PPT 20 (polypropylene).

6_02_11

6_03_11

The first thing to catch your eye is the wheelbase, which is now 3.9˝ (100 mm) longer. At the same time, the vehicle retains the compact external dimensions that are typical of the sports car. The length was increased by only 2.2˝ (56 mm). To achieve this, the overhangs were shortened by 1.26˝ (32 mm) at the front and 0.47˝ (12 mm) at the rear. The vehicle height was reduced by 0.23˝ (6 mm) for the Carrera and 0.27˝ (7 mm) for the Carrera S while retaining the passenger compartment height.

The windshield is more curved, giving the vehicle an even more sweeping, coupé-style character.

The window design, now featuring black aluminum trim strips for the first time, also makes a decisive contribution to the new appearance. The new optional high-gloss anodized aluminum trim strips also emphasise the length and dynamic look of the 6_04_11

170

911 Carrera models.

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Side view

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911 Carrera 911 Carrera S

6.3 Rear view The rear apron has been redesigned to take account of aerodynamic and thermodynamic requirements:

Body exterior

• The tail lights are designed entirely using LED technology • Their narrower shape means that they integrate perfectly into the rear apron

6

In addition to the high-gloss chrome model designation, all 911 Carrera models feature the chrome-colored PORSCHE logotype above the model designation.

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The rear apron is made from the material PPT 20 (polypropylene).

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911 Carrera 911 Carrera S

Body exterior

6

6.4 Occupant protection General The comprehensive occupant protection system used in the 911 Carrera models (991) includes the following main components: • Two-stage, full size airbags for the driver and passenger • Porsche Side Impact Protection System (POSIP) comprising: - Head airbags for driver and passenger integrated in the door panels - Thorax side airbags in the front seats for driver and passenger - Side impact protection in the doors • Safety steering column • 3-point automatic seat belts

• Roll-over sensor • ISOFIX brackets on the rear seats, top-tether anchor on the rear shelf and ISOFIX preparation on the passenger seat for securing a child seat

6_06_11

The driver and passenger are protected by full-size airbags, which are deployed in two stages depending on the severity and type of accident, e.g. head-on or diagonally from the front. Two sensors at the front of the vehicle detect a crash together with the sensor technology in the airbag control unit and accurately evaluate this information in just fractions of a second. In less severe accidents, the occupants are restrained by the first stage. The airbag is softer in this stage, reducing the stress on the occupants.

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• Seat-belt pretensioners (front) and force limiters (front)

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911 Carrera 911 Carrera S

The standard Porsche Side Impact Protection System POSIP includes front thorax side airbags integrated in the seat, head airbags in the door panels as well as side impact protection in the doors. All 911 Carrera models also feature a standard safety steering column as well as 3-point automatic seat belts with pyrotechnic seat-belt pretensioners (front) and energy-absorbing structures in the dashboard. A

Body exterior

6

roll-over sensor detects an imminent roll-over and automatically activates the head airbags and seat-belt pretensioners.

For easy and secure installation of child seats in all 911 Carrera models, an ISOFIX mounting is installed as standard on the rear seats and a top-tether anchor (additional mounting point for AUS) is installed on the rear shelf, while a preparation

child seats with the particularly safe and standardized ISOFIX system can be used.

The passenger’s airbag can be deactivated for this purpose using a key-operated switch.

Airbag components The airbag control unit performs the following tasks: • Supplying the ignition energy • System and component monitoring • Fault detection and storage • Activation of airbag warning light in the event of an accident • Detection of vehicle deceleration • Reliable triggering of the system The airbag control unit (see arrow in Fig. 6_07_11) is secured to a holder on the

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for ISOFIX mountings is optionally available for the passenger seat. This means that

6_07_11

center tunnel with three M6 cap nuts.

The front sensors (see arrow in Fig. 6_08_11) are used for early detection of the severity of an accident in the event of a head-on collision and are installed on the left and right front fenders, near the headlights.

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911 Carrera 911 Carrera S

6

collision and are installed on the inside of the left and right door sills.

6_09_11

The pressure sensors (see arrow in Fig. 6_10_11) are used for detection of a side collision and are clipped onto the left and right door mounting brackets.

6_11_11

!

Danger of serious or fatal injuries for the passenger if the passenger’s airbag remains switched off after removing the 6_10_11

child seat. The passenger’s airbag must be switched on after removing the child

Switching the passenger’s airbag on and off

seat.

The passenger’s airbag can be switched off or on using the emergency key (see Fig. 6_11_11).

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Body exterior

The side sensors (see arrow in Fig. 6_09_11) are used for detection of a side

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911 Carrera 911 Carrera S

PASS AIR BAG OFF warning light If the airbag on the passenger’s side (seat 2) is switched off, the PASS AIR BAG OFF warning light lights up continuously on the overhead operating console

Body exterior

when the ignition is switched on.

6

Child seat with ISOFIX system The retaining eyelets (A) of the ISOFIX child seat anchorage are located on passenger’s seat on the seat surface (depending on equipment version) and on the rear seats.

removed.

The bottom parts of the backrests are pulled out at the top center (velcro fastener) and detached at the ISOFIX brackets.

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When installing on the rear seats, the bottom parts of the backrests must first be

6_12_11

!

The key-operated switch for switching off the passenger's airbag, the PASS AIR BAG OFF warning light and the ISOFIX

mounting are not installed at the factory.

These can be retrofitted by a Porsche dealer.

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6_13_11

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911 Carrera 911 Carrera S

6

There are two fold-out cupholders behind the panel above the glove compartment.

The cupholders can be pulled out to accommodate larger containers.

6_15_11

6.6 Glove compartment The glove compartment can be opened by pulling the handle in direction of arrow.

There is a holder on the inside of the glove compartment lid for clipping in a ball-point pen.

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The USB/iPod® and AUX interfaces are located in the glove compartment.

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Body exterior

6.5 Cupholders

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911 Carrera 911 Carrera S

The storage compartment can be accessed by pressing the button on the passenger side of the armrest. The lid then opens automatically.

Body exterior

6 cardiagn.com

6.7 Center console storage

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6_19_11

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Body exterior

6

6.8 Luggage compartment lid and engine cover The luggage compartment lid or engine cover can be opened by actuating the corresponding pull-button A or B next to the driver’s seat.

If a lid is not closed properly, a message will appear on the multi-function display in

6_22_11

6_20_11

6_21_11

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the instrument panel while driving.

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911 Carrera 911 Carrera S

The sun visor can be swivelled down to protect against glare from the front. To prevent glare from the side, the sun visor can be unclipped from the inner bracket and swivelled in front of the door window.

6_23_11

Body exterior

6 cardiagn.com

6.9 Sun visor

Vanity mirror The vanity mirror on the back of the sun visor is concealed by a cover. The vanity mirror light comes on when you open the cover.

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911 Carrera 911 Carrera S

7 Body – Interior equipment

7.1 General The interior of the new 911 Carrera (991) models has been completely redesigned.

The interior design of both variants has been extensively standardized.

Body – Interior equipment

All 911 Carrera models are equipped with a partial leather interior in four attractive

7

colors as standard. In addition, customers can also optionally choose from a full leather interior in smooth-finish leather in the four standard colors, a leather interior in two-tone smooth-finish leather in two colors combinations, a leather

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interior in special colors or a natural leather interior in two colors.

7_01_11

7.2 New operating concept The new elevated center console with its raised shift mechanism adds structure to the passenger compartment and emphasizes the cockpit-like character of the 911 Carrera. The driver and passengers feel more as if they are an integral part of the vehicle - there is a more sporty feeling inside the vehicle.

7_02_11

General

181

New operating concept

181

Steering wheel

182

Seats

183

New Porsche key

185

Luggage compartment and storage

186

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911 Carrera 911 Carrera S

Body – Interior equipment

7

The buttons are combined into function groups. They have been arranged in such a way as to allow fast, uncomplicated and intuitive operation for the driver.

The combination control stalk allows the driver to control the wiper and washer system, direction indicators, cruise control and functions of the multi-function display without taking the hands off the steering wheel.

The five round instruments, which are typical of the 911, provide all the important information about the operating condition of the vehicle. As on previous models, the central tachometer - as the most important element for the driver - contains all the main information, such a speed, rpm, selected gear and warning and indicator

7.3 Steering wheel The sports steering wheel, with a steering wheel rim in smooth-finish leather, is standard for all models and includes mechanical steering column adjustment. The adjustment travel for steering wheel reach adjustment has been increased by 0.39˝ (10 mm). This enhances operating comfort and driver’s seat ergonomics for sporty driving.

Models equipped with PDK can be shifted manually using shift buttons on the steering wheel. The shift buttons themselves have a high-quality finish. The steering wheel can be adjusted electrically for the first time in conjunction with the fully elec7_04_11

tric sports seats (14-way) and the Adaptive Sports seats Plus (18-way).

In contrast to the previous model, the steering wheel trim and airbag module are now always finished in the interior color. Steering wheel heating is available as an option. The SportDesign steering wheel continues to be available as an option. Shift paddles made of light alloy are used in combination with PDK. With the multi-function steering wheel in leather, the driver can quickly and easily operate a variety of functions by means of multi-function buttons and thumb rollers, e.g. audio/communication, on-board computer and telephone, even while driving.

The multi-function steering wheel with trim elements is available in Mahogany, 7_05_11

Aluminum Look and Carbon. In such cases, the steering wheel rim includes decorative inlays. The functions are the same as those of the leather multi-function steering wheel. The multi-function steering wheel with trim elements is always equipped with steering wheel heating.

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lights.

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911 Carrera 911 Carrera S

7.4 Seats Front seats Seat fore/aft adjustment has been extended by 0.39˝ (10 mm) to the rear compared with the previous models, in order to meet the comfort requirements of tall drivers even more effectively.

Body – Interior equipment

7

Seat ventilation is available for the first time for all seat variants (in conjunction with heated seats). The new standard sports seats with 4-way electrical adjustment offer the following adjustment options: • Backrest angle (electrical) • Seat height (electrical)

The optional fully electric sports seats (14-way) can be adjusted even further.

They meet the highest standards in terms of comfort. In addition to the sports seat features, they also offer the following functions: • Electrical seat cushion depth and angle adjustment • 4-way lumbar support for driver and front passenger • Electrical steering column adjustment • Memory package The memory package includes storage of the following individual ergonomic settings: • Driver’s seat, electric steering column and exterior mirrors • Comfort settings (exterior/interior lights, wipers, air conditioning, door locks, instrument cluster and optional PCM)

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• Fore/aft adjustment (mechanical)

7_06_11

7_07_11

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Body – Interior equipment

7

The Sports seats Plus offer even more lateral support than the standard sports seats. They have the same adjustment options as the sports seats, but also offer the following features: • Higher side bolsters on the seat cushions and backrests • More pronounced shaping in the shoulder area • Custom seam pattern

The Adaptive Sports seats Plus (18-way) with memory package are available for optimum lateral support in every situation. Particularly impressive here is the sporty design and the additional lateral support provided by the following features: • Higher side bolsters on the seat cushions and backrests

• Custom seam pattern

In addition to electrical adjustment as per the fully electric sports seats, this option also includes electrical adjustment of the following: • Seat cushion side bolsters • Backrest side bolsters

7_08_11

The adaptive sports seats can be precisely adapted to the body contours of the driver by way of individually inflatable air cushions in the side bolsters. The seat therefore offers optimum lateral support even during particularly sporty driving.

7_09_11

!

The settings for the seat cushion and backrest side bolsters cannot be memorised.

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• More pronounced shaping in the shoulder area

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911 Carrera 911 Carrera S

The two rear seats are separated by a redesigned center tunnel and also comprise the two lumbar parts and the folding backrests.

Body – Interior equipment

7 cardiagn.com

Rear seat system

7_10_11

The backrests of the rear seat system can be split-folded, which enables the luggage compartment volume to be increased from 5.29 cubic feet (150 l) to up to 7.23 cubic feet (205 l).

7_11_11

7.5 New Porsche key As already introduced with the new Cayenne and Panamera models, the Carrera models also come with the new attractive car-shaped Porsche key.

The vehicle can be unlocked and locked using the key or without the key in the case of Porsche Entry & Drive, depending on vehicle equipment.

7_12_11

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Body – Interior equipment

7

7.6 Luggage compartment and storage The redesigned passenger compartment is based on a well-considered concept that includes a range of practical storage options. The 911 is therefore well-equipped for a wide range of day-to-day requirements. It can easily transport two people and their luggage.

The following storage options are available: • Lockable glove compartment • Two cupholders integrated in the dashboard • Storage compartment underneath the center console armrest • Storage compartment in the center console, ashtray with the smoker package

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• Front door pockets in the door panels

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911 Carrera 911 Carrera S

8 Heating and air conditioning

8.1 General For the first time, the 911 Carrera (991) sports car is equipped with 2-zone automatic climate control. This allows independent control of the following in the

Heating and air conditioning

passenger compartment for the driver and passenger: • Temperature

8

• Air distribution

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• Air flow

8_01_11

Extended air-conditioning functions To provide enhanced air-conditioning comfort for sports cars, the “extended air-conditioning functions” that are available on the Cayenne and Panamera can now be used in the 911 Carrera for the first time. The functions listed below can be selected via the on-board computer of the instrument cluster. The extended air-conditioning functions in the sports car include: • Automatic air-recirculation mode (use of an air quality sensor) • Air flow adjustment (individual blower/air flow regulation) • Extended ventilation panel

General

189

Ventilation

190

Operation

195

Refrigerant circuit

205

Actuators and sensors

207

Topology of the air-conditioning system

210

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911 Carrera 911 Carrera S

8

Heating and air conditioning

8.2 Ventilation Air and flap control (intake tube) The fresh-air supply for the heater is located in the right plenum panel (technology space). For the first time in the sports car, two filters are used to clean the intake air: • Pre-filter (1) • Main filter (in the heater, as in the Cayenne) This pre-filter (1) is located in the intake tube housing (3). The fresh-air/recirculation

2

flap (2) is clearly visible when the intake tube cover is removed. This makes it easy

3

to perform a function test of these flaps.

8_02_11

Air and flap control (air outlet on dashboard) The picture below shows the configuration of the two air-conditioned zones on the

!

dashboard. The temperature can be set and controlled independently for both

Located behind the fresh-air/recirculation

zones. This zone configuration must also be taken into account for the two vents of

flap (2) is the flap for ram-air

the extended ventilation panel.

compensation – this air flap starts to close at speeds > 49.7 mph (80 km/h).

This does not completely shut off the fresh-air supply.

1 Defroster (front and side) 2 Extended ventilation 3 Side/center left ventilation (1-zone) 4 Side/center right ventilation (2-zone) 5 Air intake, heater 6 Passenger compartment temperature sensor 7 Sun sensor 8_03_11

8_04_11

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911 Carrera 911 Carrera S

Air and flap control (air ducts)

8

The air is distributed to the individual vents in the dashboard via air ducts. These air ducts are mounted on an intermediate piece, which is integrated in the dashboard.

Heating and air conditioning

The air-conditioned air from the heater is routed via individual connection openings (1 to 4) from the heater, through the integrated intermediate piece, via the air ducts to the individual outlet openings.

1

1 Defroster (front and side) 2 Extended ventilation zone) 4 Side/center right ventilation (passenger’s zone)

3 2

Driving direction

4 8_05_11

The temperature sensors for the passengers are located in the air ducts just upstream of the outlets in the dash board. The system has a temperature sensor for both the driver’s and passenger’s zone.

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3 Side/center left ventilation (driver’s

!

The temperature sensor is locked during installation by turning it 90°.

8_06_11

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911 Carrera 911 Carrera S

Heating and air conditioning

8

Air and flap control (servo motors for driver’s and passenger’s side) Most of the servo motors for flap control are located on the heater on the left and right, directly on the air-mixing chamber. As this is a 2-zone system, there is also at least one separate servo motor for the temperature mixing flap on each side (driver’s and passenger’s zone). There are also a number of temperature sensors mounted directly on the heater housing. The exact positions of the individual servo motors and sensors are shown in the illustrations below.

!

The evaporator temperature sensor can be removed and installed with the water

Driver’s side

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heat exchanger installed (closed system).

3

2 1

1 Servo motor for footwell

8

2 Servo motor for temperature mixing flap (left) 3 Servo motor for defroster 4 Servo motor for “extended

9

ventilation”

10

8_07_11

5 Servo motor for side/center ventilation, left and right

Passenger’s side

6 Servo motor for temperature mixing flap (right) 5

7 Temperature sensor for footwell 4

(right) 8 Temperature sensor for footwell (left)

6

9 Evaporator temperature sensor 10 Condensed water drain tube

7 Driving direction

10

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911 Carrera 911 Carrera S

Air and flap control (air outlet in heater)

8

The illustration below shows various servo motors and the air vents of the heater.

The air flows from the vents (6 to 8) are routed to an intermediate piece, which is

Heating and air conditioning

integrated in the underside of the dashboard. Air ducts connected here route the air flow to the intermediate piece, then to the vents in the dashboard. The vents in the dashboard for the passenger air flow (8) can be adjusted or closed manually using

!

an air flow adjusting wheel.

The air flows for the footwell (9) are routed to the footwell via separate air ducts,

The illustrated servo motors for air

which are connected to the outlet connection pieces of the heater. The air flow for

distribution (1, 3) always move the flaps

the driver’s or passenger’s side passes the temperature sensor for the footwell

for both temperature zones via a

(11). This is taken into account by the OAU (Operating and Air-conditioning Unit) in

“through shaft”.

automatic mode.

This also applies to the servo motor for

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the passenger blowers on the left and right in the dashboard (side/centre).

8

7

6

7

8

3

1 Servo motor for footwell

4 5

2

2 Servo motor for temperature mixing flap (left) 3 Servo motor for defroster 4 Servo motor for ram air

1

5 Servo motor for fresh air/ recirculated air

11

6 Air outlet for “extended ventilation” 7 Air outlet for defroster

9

10

12

9

11

8 Air outlet for passenger ventilation (side/center) 8_09_11

9 Air outlet for footwell 10 Condensed water drain tube

Similar to the Panamera, there are individual servo motors located on the air intake of the heater for fresh-air/recirculation mode and for ram-air compensation.

11 Driver's and Passenger's side footwell temperature sensors.

12 Service flap for main filter

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911 Carrera 911 Carrera S

Heating and air conditioning

8

Cross section of a temperature zone Behind the evaporator, the entire air flow (grey arrows) is routed separately for the driver’s and passenger’s side through the heater (partition). The temperatures can be controlled independently in the temperature mixing chambers through which the air flows (temperature zones). There is a temperature mixing flap (7) for each of the temperature zones (right and left). This temperature mixing flap is activated using the respective servo motor for the zone. The tempered air in the individual temperature zones can then be routed through the air vents of the air conditioner via air

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ducts to the air vents, depending on the setting.

Temperature zone in the heater (passenger)

1

1 Defroster

2

2 Passenger ventilation (side/center)

6

3 Footwell 4 Evaporator

6

5 Water heat exchanger 6 Air flow flap

4

7

7 Temperature mixing flap 8 Temperature sensor for footwell 9 Condensed water drain tube

5

8 3

9

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911 Carrera 911 Carrera S

8.3 Operation The OAU (Operating and Air-conditioning Unit) in the center console permits adjustment of the air-conditioning and other operating functions. The control unit

Heating and air conditioning

integrated in the operating unit also regulates and controls all the heating and air-conditioning system components required for passenger compartment air

8

conditioning, such as activation of servo motors or of the air-conditioning compressor.

2-zone air conditioning (automatic) As of model year 2012, the air-conditioning system allows different temperatures to

and controlled uniformly on both sides. The vents can be adjusted or closed individually to set the desired air flow.

!

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be selected for the driver and passenger. The air flow and air distribution are set

The current temperature settings are shown in a separate display for the driver and passenger.

Temperatures of between 60.8° F. (16° C.) and 85.1° F. (29.5° C.) can be selected (recommendation: 71.6° F. /22° C.).

8_11_11

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Heating and air conditioning

8

Functions of the air-conditioning system The most important functions of the air-conditioning system are listed below: • Automatic mode • MONO mode • Defrost mode • AC MAX mode • Air-recirculation modes • Manual blower influencing

Automatic mode Automatic mode assumes fully-automatic control of the passenger compartment

depending on various influencing factors (e.g. sunlight, air quality, intake air temperature). Changes to the air flow and air distribution are applied to both sides.

MONO mode

!

In MONO mode, the air-conditioned zone for the passenger depends on the settings of the driver’s air-conditioned zone. To activate MONO mode, press and hold the

To deactivate MONO mode, press the

AUTO button until MONO appears in the display. The passenger compartment tem-

AUTO button or the TEMP button on the

perature settings for the driver’s and passenger’s side can now be changed

passenger’s side briefly.

together using the TEMP button on the driver’s side.

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temperature for the driver’s and passenger’s zone, which can be pre-set separately,

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911 Carrera 911 Carrera S

Defrost mode

8

When defrost mode is activated (indicator light in the button lights up), the following settings are made automatically by the OAU:

Heating and air conditioning

• Air distribution upwards only • Temperature mixing flap is set to maximum heating • Air-recirculation mode is exited • AC mode is activated • AUTO function (on both sides) is exited

OAU

Operating and Air-conditioning Unit (control unit of air-conditioning system)

Topology for defrost mode (one zone shown here)

OAU

Defrost button (in OAU)

B

Ignition lock (terminal 15)

BCM

Body control module front (front-

M2 A

M3 M4 M5 CAN

B

LIN

BCM

MMI

C

CAN

A

DME

DME control unit

M1

Servo motor for defroster

M2

Fan motor

M3

Servo motor for temperature mixing flap

M4

Servo motor for fresh-air/ recirculation flap

Gateway CAN

end electronics)

DME 8_12_11

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M1

A

M5

Air-conditioning compressor

CANA

CAN drive

CANC

CAN comfort

CANMMI CAN Man Machine Interface LIN

Local Interconnect Network

AC MAX mode In AC MAX mode (indicator light on the button lights up), the maximum cooling capacity of the entire system is focused on the two zones. The following settings are made automatically by the OAU for the two zones for rapid cooling: • Temperature mixing flaps are set to maximum cooling • Blower runs at maximum speed • Passenger vents are primarily supplied with air • Recirculated air is set for a short time In AC MAX mode, there is no automatic control of the passenger compartment temperature.

8_13_11

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Heating and air conditioning

8

Air-recirculation modes The following air-recirculation modes are available in the sports car as of model year 2012 and can be activated in various situations: • Manual air-recirculation mode • Automatic air-recirculation mode for poor air quality • Automatic air-recirculation mode for supporting the refrigerant circuit • Automatic air-recirculation mode after actuation of the windshield wiper/ washer system

Manual air-recirculation mode Manual air-recirculation is “forced air-recirculation”. “Forced air-recirculation mode”

1. Air-recirculation by pressing the button in the OAU: This air-recirculation mode can be selected to prevent unpleasant odors by pressing the air-recirculation button in the OAU. 2. Air-recirculation in AC MAX mode: 8_14_11

!

The recirculation flap is closed in order to achieve the maximum cooling capacity (see also AC MAX mode).

When defrost mode is selected,

Automatic air-recirculation mode

air-recirculation mode is exited (if set)

1. Automatic air-recirculation mode for poor air quality:

and fresh-air mode is restored.

The emission-related concentration of pollutants in the intake air is determined by means of an air quality sensor in the intake duct. If this sensor detects exhaust gas in the intake air, the switch to air-recirculation mode is initiated.

2. Automatic air-recirculation mode for supporting the refrigerant circuit: When the outside temperature is above 77° F. (25° C.), air-recirculation mode is set automatically in order to achieve the maximum cooling capacity. This guarantees rapid cooling of the passenger compartment to the desired temperature set in the OAU. 3. Automatic air-recirculation mode after actuation of the windshield wiper/washer system: Air-recirculation mode is set for approx. 20 seconds when the outside temperature is >41° F. (5° C.).

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is set by the system during the operating states described below.

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911 Carrera 911 Carrera S

Topology of the air-recirculation modes

8

Heating and air conditioning AQS

OAU M

NTC OAU

TEMP

Operating and Air-conditioning Unit (control unit of air-conditioning system)

M CAN MMI CSCM

flap

Gateway CAN C

AQS

Air quality sensor

NTC

Outside temperature

B

Wiper stalk

TEMP Passenger compartment temperature sensor 8_15_11

CSCM Combined steering column module CANC CAN comfort

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B

Motor for fresh-air/recirculation

CANMMI CAN Man Machine Interface Extended air-conditioning functions The “extended air-conditioning functions” allow greater personalization and provide enhanced comfort for the air conditioning in the passenger compartment. The relevant settings are made in the multi-function display of the instrument cluster.

The functions listed above are available for the sports car: • Automatic air-recirculation mode (use of an air quality sensor; see above) • Air flow adjustment (soft/normal/strong) • Extended ventilation panel (on/off) The “extended ventilation panel” on top of the dashboard can be switched on or off separately, for example. The air flow in the passenger compartment is therefore less direct. The air conditioning regulates the emerging air flow automatically.

8_16_11

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8

!

Seat air conditioning Seat air conditioning for the front seats is regulated with buttons in the OAU for seat heating and seat ventilation respectively. Seat heating and seat ventilation each have three settings and OFF. The selected function is shown using three function displays (LEDs) in the buttons.

Operating principle seat heating and seat ventilation

Seat ventilation is only available in

The heating and ventilation functions can be switched on or off in their three

combination with seat heating.

settings independently. Regulation of the seat heating and seat ventilation depends on the relevant values of the temperature sensors in the seat surfaces and on the passenger compartment temperature.

energy management in the gateway checks whether the request for seat heating or

If the engine running signal is not present

seat ventilation can be met. The engine running signal or the ignition switched on

in the OAU, the seat heating and seat

information (terminal 15) is required for this analysis.

ventilation are either only partly available

If the available energy does not exclude the possibility of using seat heating or seat

or, due to the vehicle voltage status

ventilation, the gateway sends corresponding information (bit) on the CAN MMI. As

(energy management), not available at

soon as this information is detected by the OAU, the desired function or setting is

all.

executed directly by the control unit of the air-conditioning system.

OAU

Operating and Air-conditioning Unit (control unit of air-conditioning system)

B

Ignition lock (terminal 15)

BCM

Body control module front

Topology of the seat heating and seat ventilation

(front-end electronics) ACR/L

Button for seat heating, right/left

AMR/L

Button for seat ventilation,

NTC R TEMP

right/left C1/2R/L Heating element (seat/backrest), right/left

AC R

C1 R

C2 R

M1 R

M2 R

C1 L

C2 L

M1 L

M2 L

OAU

AM R

M1/2R/L Fan module (seat/backrest), right/left NTCR/L Temperature sensor in the seat

AC L AM L

surface, right/left

CAN MMI

TEMP Passenger compartment temperature sensor DME

DME control unit

CANA

CAN drive

CANC

CAN comfort

CANMMI CAN Man Machine Interface LIN

Local Interconnect Network

200

B

LIN

NTC L BCM

Gateway CAN C

DME CAN A 8_17_11

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However, before the selected function (heating and/or ventilation) is executed,

!

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911 Carrera 911 Carrera S

Seat ventilation

8

Use of seat ventilation can be combined with temperature control for seat heating.

This ensures the continuous removal of moisture while maintaining a pleasant

Heating and air conditioning

seat-surface temperature.

Seat ventilation components

!

The system, which can be ordered as an option together with seat heating, comprises the following main components for the driver and passenger:

A temperature sensor is integrated in the

• Fan modules for the seat surface (1) and backrest (2)

heating element in the seat surfaces of

• Air ducts in the seat surface and backrest (see arrows for air routing)

both seats.

• Air-permeable cushioned mats

A temperature of at least 59° F. (15° C.)

• Wiring harness (not described here)

must be measured both by the

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• Separate three-stage operating button in the OAU (climate control panel)

passenger compartment temperature

sensor and the two temperature sensors in the seats.

Below this temperature, the seat

ventilation function is not available or is switched off, if necessary, in order to prevent excessive cooling.

!

The fan modules are no longer activated or switched off automatically by the

climate control panel when the voltage is less than 9 volts or more than 16 volts.

8_18_11

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Heating and air conditioning

8

Rear window heating Operating principle The rear window heating can be switched on and off using the button in the OAU. The active mode is indicated by way of an LED in the button. The operating time is dependent on the outside temperature.

The request bit for heating and the value of the outside temperature sensor are sent by the OAU on the connected CANMMI. Energy management in the gateway checks whether the request for rear window heating can be met (the engine running signal is required for this analysis).

If the available energy does not exclude the possibility, the gateway sends the corresponding request bit for heating on the CANcomfort. As soon as the request is side) is activated by the rear-end electronics. The rear window heating is supplied with positive potential (terminal 87) via the relay.

Activation of the relay driver is sent on the CANcomfort as a “confirmation bit” by the rear-end electronics. This confirmation bit is used by both door control units for

8_19_11

controlling the door mirror heating.

Topology of the rear window heating system

OAU

Operating and Air-conditioning Unit (control unit of

OAU

Gateway

B1

Rear-end electronics

C

Heated rear window

CR

Mirror heating, right

CL

Mirror heating, left

DR

Door control unit, right

DL

Door control unit, left

DME

DME control unit

NTC

Outside temperature sensor (located in right side radiator intake)

RLY

Rear window heating relay

CANA CAN drive

C

(relay)

air-conditioning system) B1

RLY

CAN MMI

NTC CAN C DME

DR

CR

CAN A DL

CL

CANC CAN comfort CANMMI CAN Man Machine Interface

202

8_20_11

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detected by the control unit of the rear-end electronics, the relay driver (control

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911 Carrera 911 Carrera S

Steering wheel heating

8

Operating principle The steering wheel heating can be switched on and off by way of a button on the

Heating and air conditioning

back of the steering wheel (6 o’clock spoke). The request for steering wheel heating and the value of the temperature sensor in the steering wheel rim are sent via the steering wheel contact loop to the CSCM (combined steering column module) using

!

a conventional line.

The CSCM receives additional input information (e.g. passenger compartment temperature, engine running detected) via the CAN bus for controlling the steering

Activation and deactivation of the system

wheel heating.

is indicated in the instrument cluster.

If the available energy does not exclude the possibility, the CSCM supplies current

passenger compartment sensor, which is provided by the OAU via the gateway, is used as the main input variable for this control.

Topology of the steering wheel heating

1

CSCM

4

2

3

1

Heated steering wheel switch

2

Instrument cluster

3

Display in instrument cluster

4

Temperature sensor (NTC) in steering wheel

5

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to the heating foil/heating fabric on the steering wheel rim. The value of the

5

Heating foil/heating fabric in steering wheel

CSCM Combined steering column module CAN C B

BCM

Ignition lock (terminal 15)

BCM

Body control module front

Gateway

(front-end electronics)

CAN C TEMP

B

TEMP Passenger compartment temperature sensor

OAU OAU

CAN MMI

Operating and Air-conditioning Unit (control unit of

DME CAN A

air-conditioning system) 8_21_11

DME

DME control unit

CANA CAN drive CANC CAN comfort CANMMI CAN Man Machine Interface

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Heating and air conditioning

8

Automatic load switch-off If the charging condition of the battery is critical, the following air-conditioning or heating functions are restricted initially and then switched off completely at a later time if necessary: • Seat heating • Seat ventilation

!

In cases of extreme engine load, the

• Rear window heating/door mirror heating • Fresh-air fan (blower) • Air-conditioning compressor

air-conditioning compressor is switched off for a short time in order to guarantee

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sufficient engine cooling.

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8.4 Refrigerant circuit

8

The refrigerant circuit is comparable with that of the previous model.

Heating and air conditioning

1 Compressor 2 Condenser (left and right) 3 Filter dryer/fluid tank 4 Expansion valve 5 Evaporator air quality sensor)

8_22_11

!

The air-conditioning compressor

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A Air intake tube for pre-filter (including

The swash plate adjustable compressor is comparable with the compressor of the

(controlled externally) has been taken

current 997 model line in terms of function. It uses an electronic control valve for

from the previous model.

adjustment (angle of attack) of the swash plate in order to change the stroke (refrigerant delivery rate).

1 Electronic control valve 2 Swash plate

!

The compressor has no magnetic clutch.

This means that the compressor is always driven when the engine is running.

8_23_11

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Heating and air conditioning

8

The position of the filter dryer equipment has been changed compared with the previous model. The picture below shows the new position of the dryer. It is located in an opening between the right spring strut mount and the firewall. The pressure sensor is integrated in the refrigerant line on the high-pressure side in the immediate vicinity of the dryer.

!

The dryer can be accessed for repair work via the right wheel housing – after

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removal of the wheel housing liner.

1

1 Filter dryer 2 Pressure sensor

8_24_11

8_25_11

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8.5 Actuators and sensors General For the air-conditioning function, the OAU (Operating and Air-conditioning Unit) has

Heating and air conditioning

the following sensors on the input side: • Pressure sensor for refrigerant pressure (pulse width modulation)

8

• Outside temperature sensor • Intake air temperature sensor • Passenger compartment temperature sensor • Evaporator temperature sensor • Temperature sensor for passenger vents, left/right • Temperature sensor for footwell, left/right • Sun sensor, left/right (dashboard)

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• Air quality sensor The flaps, fan controls and fresh-air controls (e.g. air-recirculation mode) are activated by the OAU using these sensors. Due to their function and significance for air-conditioning system control, detailed information on the highlighted sensors is provided on the following pages.

Pressure sensor for refrigerant pressure (pulse width modulation) The pressure sensor for refrigerant pressure is used to determine the current pressure in the refrigerant circuit. It detects the refrigerant pressure and converts the physical variable (pressure) into an electrical signal. Data is exchanged directly via a PWM interface between the operating and air-conditioning unit (OAU) and the refrigerant pressure sensor.

Interface for the operating and

Pulse width modulation

air-conditioning unit (OAU) Temperature application range

-40° F. to 266° F. (-40° C. to 130° C.)

Refrigerant pressure measured variable

Pressure in bar

Refrigerant pressure measuring range

0 to 580 psi (0 to 40 bar)

8_25_11

1 Filter dryer 2 Pressure sensor

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Heating and air conditioning

8

Passenger compartment temperature sensor The passenger compartment temperature is measured using a sensor, which operates according to the infrared measuring principle. This means that the sensor uses thermal radiation for temperature measurement. The sensor is located directly in the dashboard, as in the Panamera and Cayenne. The sensor must not be

3

8_26_11

1

3

2

2 1

Infrared radiation from emitting

1

substance (surface) 2

Infrared radiation sensor

3

Sensor electronics

8_27_11

8_28_11

Evaporator temperature sensor The evaporator temperature sensor value is used as the main input variable for the externally-controlled compressor. The sensor is located on the right side of the air mixing chamber in the heater unit housing approx. 5 mm behind the evaporator (not in the slats).

!

The evaporator temperature sensor and the intake air temperature sensor of the air-conditioning system are identical.

Resistance at T = 32° F. (0° C.): 9.0 kOhm (1% deviation).

1 Evaporator temperature sensor

BEHR 8_29_11

208

8_30_11

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covered or taped over in order not to impair its functionality.

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911 Carrera 911 Carrera S

Air quality sensor

8

The air quality sensor (AQS) is capable of detecting both CO and NOx pollutants.

The air quality sensor is used primarily for automatic air-recirculation control. The

Heating and air conditioning

air quality sensor is located directly adjacent to the air intake of the intake tube.

This ensures that air contaminants from exhaust gas can be detected as quickly as possible – before entering the air distribution system.

3

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2

1 2

8_31_11

3 1

Air quality sensor

2

Pre-filter

3

Intake tube housing

8_32_11

Sun sensor The sun sensor is still located in the center of the dashboard and is supplied with a 5 volt reference. It is a new design for the 2012 Carrera (991) models. It contains two photo diodes which are inputs used by the left and right zones. The two sensor voltages change according to the intensity of the sun light and will only affect the temperature inside the vehicle as well as the fan speed after at time constant. This is necessary to avoid changes when brief changes of sun light occur, (ie. Driving through a tunnel or on tree lined streets).

The diagram at left shows the direct relationship between the sun intensity

Voltage

and the voltage sent to the OAU from the 2 sides via a LIN Bus. The nominal operating range is between .5 and 3.5 volts. The tolerance between the 2 sensor sides must not exceed 2% over the lifetime of the sensor.

Sun Intensity W/m2

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Heating and air conditioning

8

8.6 Topology of the air-conditioning system The control unit of the air-conditioning system (Operating and Air-Conditioning Unit) communicates with other control units via CANMMI and with external devices and sensors via the LIN bus. The blower and flaps on the heater as well as the air quality sensor on the air intake tube housing are activated via the LIN bus.

Diagnosis 500 kbps

Gateway

Drive 500 kbps

Chassis 500 kbps CDR-31 Comfort 500 kbps PCM 3.1

MOST 20 Mbps Man Machine Interface

OAU

AQS

Crash risks 500 kbps

LIN 19.8 kbps

LIN

Heater unit

Sun sensor

Xi

Switch module

8_33_11

Control units connected to the CAN MMI (e.g. instrument cluster)

OAU Operating and Air-conditioning Unit

The air-conditioning compressor is activated directly via a PWM (pulse width modula-

AQS Air quality sensor

tion) signal and is therefore not included in the topology.

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Xi

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911 Carrera 911 Carrera S

9 Electrics and electronics

9.1 General The 911 Carrera (991) models offer enhanced sportiness combined with higher comfort and day-to-day usability. The standard equipment has been significantly

Electrics and electronics

improved compared with the previous models and new attractive options are available. The electrical equipment in the Carrera 991 has been completely

9

revamped and a large number of components and systems have been adopted based on the electrical concept of Panamera and Cayenne 2011. The modified/

9_01_11

General

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new components will be described in detail in the following Chapter 9.

213

Vehicle electrical system/energy management

214

Auto Start Stop function

226

Lighting

227

Front-end electronics control unit

235

Rear-end electronics control unit

242

Instrument cluster

244

ParkAssist

246

Infotainment

248

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911 Carrera 911 Carrera S

Electrics and electronics

9

9.2 Vehicle electrical system/energy management An AGM battery (Absorbed Glass Mat) 70 Ah/450 A is used as standard in the 911 Carrera (991). This meets the high requirements of the vehicle electrical system/energy management. Special microglass fiber mats are located tightly between the positive and negative lead plates of the battery and bind all of the battery acid. Thanks to the fast reaction between the acid and plate material, higher quantities of energy can be exchanged in demanding situations. The battery is maintenance-free and sealed.

The maintenance-free AGM battery offers the following advantages: • Sealed, valve-regulated battery with high cycle stability • High cold-start performance • No acid leaks in the event of housing damage, vibration-resistant,

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leak-proof and unspillable • Flexible installation and safe handling • High load capacity and longer service life • Ideal for Auto Start Stop function and recuperation

!

In the event of battery replacement, the gateway (master control unit in the battery/energy management system) must be informed of the battery manufacturer, capacity, serial number and part number with the PIWIS Tester II under the path Maintenance/Repair/ Battery replacement. This resets the maps used to calculate the battery condition.

214

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External charging/jump starting

9

Every external charging/jump starting operation on the battery must be performed at the jump start terminal at the positive battery terminal and the corresponding

Electrics and electronics

ground terminal (marked in the engine compartment). The negative battery terminal must not be used for external charging/jump starting since the battery sensor can be destroyed by voltage peaks during the charging operation/jump starting.

!

General information on the AGM battery (e.g. maintenance, charging, handling requirements) is provided in the

9_03_11

A = Positive battery terminal B = Ground point for external power supply/jump starting

Battery sensor

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Workshop Manual.

9_04_11

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Electrics and electronics

9

The battery sensor detects and calculates the energy flow and uses this information to calculate the battery condition. It is installed between the negative terminal of the battery and the ground cable to the body.

The following measured variables are detected by the sensor: • Battery current (charging current/discharge current) • Battery voltage (positive battery terminal)

9_05_11

A connector with two terminals (terminal 30/LIN) is fitted on the battery sensor control unit (see Fig. 9_05_11).

Terminal 30/battery positive is used to detect the battery voltage at the positive battery terminal and to supply power to the battery sensor (see Fig. 9_06_11). This means that it is possible to measure the charging voltage of the generator and open-circuit voltage of the battery. Using the measured values (terminal 30, battery current, measured via a shunt in the battery sensor control unit, and negative terminal temperature [NTC]), the battery sensor control unit (slave) calculates the current battery condition by way of an algorithm. This value is forwarded to the gateway (energy management master) via a LIN interface.

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• Measurement of negative terminal temperature (NTC resistor)

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911 Carrera 911 Carrera S

Electrics and electronics

9

3 +

–

2 1 Battery 2 Battery sensor control unit (ECU) 3 Gateway

1

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9_06_11

Transport lock The transport lock of the 911 Carrera (991) can be activated and deactivated with the PIWIS Tester II. For this purpose, this function is activated/deactivated in the power distributor by way of a LIN data bus. The 911 Carrera does not have a mechanical transport lock of the kind present in the power distributor of the Panamera or Cayenne 2011.

Relays/fuses/main fuse box (power distributor) Several fuse/relay boxes are installed in the 911 Carrera (991) as follows:

Installation positions of fuses/relay carriers: 1 Fuse box, battery 2 Fuses, right footwell 3 Fuses, left footwell, and relay carrier 1, above 4 Main fuse box/power distributor 5 Relay carrier 2

9_07_11

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911 Carrera 911 Carrera S

9

Electrics and electronics

Installation position 1 Fan, right, 60 A (maxi fuse) Fan, left, 60 A (maxi fuse) Electric steering 80 A (maxi fuse)

Fuse box, battery 9_07a_11 Fuses, right footwell 9_08_11

Installation position 3

Assignment of relay carrier 1: K2 = Two-tone horn relay K3 = Emergency power supply relay K6 = Fuel pump relay

K2

K3

K6 9_10_11

218

Fuses in left footwell with relay carrier 9_09_11

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Installation position 2

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911 Carrera 911 Carrera S

Installation position 4

9

The main fuse box/power distributor (MFB) has several functions: Via LIN in the main fuse box, the gateway (energy management master) can

Electrics and electronics

activate/deactivate the following relays via a LIN control unit: Terminal 30 F (30 fault) Terminal 30 SD (sockets) Terminal 30 TP (transport mode)

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Terminal 15 (terminal control)

Main fuse box/power distributor 9_11_11

There are also other main fuses/fuses in the main fuse box/power distributor.

Detailed information on this is provided on the wiring diagram (PIWIS information system/PIWIS Tester II).

Installation position 5

Assignment of relay carrier 2: K1 = DME relay K1

K2

K5

K6

K2/K6 = Engine compartment scavenging relay K7

K5 = Secondary-air pump relay K7 = Tilt relay Relay carrier 2 9_12_11

Detailed information on the fuse/relay assignment is provided on the wiring diagram (PIWIS information system/PIWIS Tester II).

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Electrics and electronics

9

External voltage supply/emergency power supply If the battery is discharged, the vehicle can be opened manually by way of a mechanical key (emergency key) at the driver's door. This provides access to the external power supply point and external power supply is possible at the emergency power pin using an external voltage source in order to access the battery (external charging/jump starting). The front lid can then be opened by pressing the remote

9_14_11

!

If the remote control has not been taught, the front lid cannot be opened using this method. Alternatively, power 9_13_11

can be supplied at the fuse carrier in the left footwell, terminal 15 (see wiring

A

Plastic clip

diagram with electrically protected cable

C

Emergency power pin (pull out)

link) in order to permit activation of the

D

Ground point

PIWIS Tester II. The front lid can then be opened electrically by way of the switch (luggage compartment lid).

220

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control (>2 seconds).

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911 Carrera 911 Carrera S

Gateway control unit The gateway control unit is the central interface of the network architecture and permits data interchange between the different networks (Controller Area Network –

Electrics and electronics

CAN, Media Oriented System Transport – MOST and the Local Interconnect Network – LIN). In addition, the gateway control unit also contains the Vehicle

9

Network State Manager, which switches the connected systems to a sleep mode after terminal 15 off (Power Down). The gateway also supports After Sales Service in fault finding (e.g. fault codes, watchdog, wake-up guardian, closed-circuit current measurement) by providing comprehensive system and diagnostic functions for monitoring network communication. The gateway includes vehicle energy management as an additional function. This function supports optimization of battery

switching off comfort functions and networks when the vehicle is not being driven.

LIN

1

5

7

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charging during driving as well as minimization of the closed-circuit current by

The red dot indicates the position of the control unit 9_15_11

!

2

LIN 8

CAN networks:

3

20 kbit/s

CAN Diagnostics

500 kbit/s

CAN Drive

500 kbit/s

CAN Chassis

500 kbit/s

CAN Comfort

500 kbit/s

CAN Crash risks

500 kbit/s

Depending on the power requirement in the network, the gateway control unit (5)

CAN Man Machine Interface

500 kbit/s

decides what capacity must be requested from the generator (1) in order to meet

MOST

4

6

9 9_16_11

20 Mbit/s

the energy requirement of the vehicle electrical system. The generator (1) generates the required amount of energy corresponding to the request from the gateway control unit (5) and supplies this to the vehicle electrical system/vehicle battery (3). The battery sensor (2) measures the energy flow quantity and forwards the result of this measurement to the gateway control unit (5). Depending on the power requirement, the gateway control unit (5) decides which loads/power distributors (4) can be activated or which loads (7= dynamic management of engine and A/C control unit, 8= closed-circuit current management, heating/ventilation allocation/HVA) can be switched off in order to ensure that the power requirement is met. It also decides when a vehicle can be switched to Auto Start Stop mode (DC/DC converter [6]) in order to guarantee the supply of power to voltage-sensitive loads (9) such as infotainment and the instrument cluster.

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Electrics and electronics

9

Vehicle electrical system recuperation The 911 Carrera (991) models now additionally feature the function of electrical system recuperation. Here, some of the kinetic energy is converted into electrical energy via the generator during vehicle deceleration phases and stored in the starter battery. As a result, less power is required to charge the battery in acceleration phases, which translates directly to lower fuel consumption.

Braking

Acceleration

Driving

9_17_11

with fuel

without fuel free charging

!

with fuel

with fuel

lower generator load

The starter battery is preferably charged by the usually otherwise lost braking energy during the braking operation. During braking, the generator power is

Recuperation display on the instrument

increased in a targeted manner by the generator regulator and the recuperated

cluster:

energy is fed into the starter battery. The voltage is then lowered again and the

During recuperation, the voltage display

energy can be fed into the vehicle electrical system in order to supply the loads.

on the instrument cluster shows a value

The increased generator power acts with a low braking torque on the crankshaft of

of between 12.0 V and 12.7 V.

the combustion engine via the belt drive. This leads to vehicle deceleration and

Recuperation is not active in Sport

therefore supports the conventional brake system. An intelligent algorithm in the

mode. The value then increases to a

energy management system evaluates various input variables of the components

minimum of 13.5 V (battery-dependent).

involved, thereby allowing active coordination of every recuperation operation based on the battery charge condition and driver request. Among other things, this control operation includes the engine control, brake pedal sensor, the AGM battery with sensor system, generator and the vehicle electrical system. The powerful AGM battery meets all requirements with respect to battery life in view of the increased number of cycles due to frequent charging and discharge.

222

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Driving

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911 Carrera 911 Carrera S

Generator The air-cooled generator (Bosch, 2.1 kW) delivers the electrical energy required to supply the electric/electronic components and systems in the vehicle. The voltage

Electrics and electronics

(12-16 V) is largely independent of load and is set by an integrated voltage regulator (BSI - bit-synchronous interface controller) in accordance with a predefined

9

characteristic. The voltage regulator (BSI) is implemented as a slave for the gateway control unit (master) and communicates via a bit-synchronous interface.

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OUTPUT CURRENT (A)

C

9_19_11

Speed rpm

The regulator and control unit communicate by way of the LIN bus.

The nominal generator current is 150 A.

A

LIN

B

LIN

C

CAN

A

Battery sensor

B

Gateway

C

Generator

D

DME

LIN

Local Interconnect Network

CAN CAN Drive

D 9_20_11

Generator control For the purpose of generator control, the information from the battery sensor (A) is transferred to the gateway (B) via a LIN (Local Interconnect Network) and the energy requirement is then calculated in the gateway (B) (intelligent algorithm). The gateway (B) sends this energy request to the generator regulator (C), which is designed as a bit-synchronous interface controller, and the generator regulator then regulates the energy requirement according to the energy request. The gateway (B) receives information about the capacity utilization status via the DFM signal (Dynamo Field Monitor) and uses these values to recalculate the energy requirement in the vehicle electrical system.

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Electrics and electronics

9

DC/DC converter A DC/DC converter (2 x 200 W) is used in combination with the Auto Start Stop system. This DC/DC converter supports the vehicle electrical system when the vehicle is restarted so that voltage-sensitive loads are not switched off as a result of low-voltage.

An Auto Start Stop cycle is initiated by the decision of the start/stop coordinator (DME). When this engine is switched off, this is followed by a period in which the electric loads of the vehicle are supplied with power from the vehicle battery (AGM).

The battery voltage falls many times below the cell open-circuit voltage. The engine is then restarted either by a driver action or by a decision of the Auto Start Stop coordinator. A first voltage dip then occurs when the starter is engaged and a

closed and upon engine breakaway.

After this, the voltage recovers as a function of the starter speed, when the starter is switched off and disengaged and when generator charging is started up to the Installation position of DC/DC converter 9_21_11

charging voltage. The size of the voltage dip depends on the temperature and all the involved components in the current path, the internal resistance and age of the battery as well as the engine counter-torque when it is turned.

Initial start/standby

1 DC/DC converter 2 Control/monitoring/diagnosis 3 Relay output 1

3 30 30f

4 Relay output 2

1 31

4

15

2 9_22_11

The relay contacts (3, 4) of the internal relays are closed in non energized position.

The connected loads are supplied with power directly from the vehicle electrical system. The DC/DC converter is not active.

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second voltage dip when the main contacts of the solenoid switch/starters are

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Restart / DC/DC converter assistance Electrics and electronics 3

9

30 30f

31

4

15

2

LIN

9_23_11

In the case of a restart, the relays (3, 4) are operated via the internal control (2) of the DC/DC converter and open the NC contacts. An existing load current (terminal 30) now flows via the power/amplifier section of the DC/DC converter and supports voltage-sensitive loads during the starting operation with voltage regulation of 12 V ±0.5 V.

1 2

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LIN

3 4

9_24_11

Start of starting

1

DC/DC active

2

Voltage regulation 12 V± 0.5 V

3

DC/DC converter voltage assistance

4

Starter (solenoid switch/main winding)

End of starting

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Electrics and electronics

9

9.3 Auto Start Stop function All 911 Carrera (991) models feature an Auto Start Stop function as standard. This switches off the engine automatically when the vehicle has come to a standstill, e.g. when waiting at traffic lights, and the brake is held. On vehicles with manual transmission, this takes place when the shift lever is neutral and the clutch pedal is not pressed. The tachometer falls to zero and the driver is informed about activation of the Auto Start Stop function by a symbol in the multi-function display (TFT display) of the instrument cluster. The audio and communication systems remain switched on despite the engine being switched off and the climate control also maintains the selected temperature level. In the NEDC, this makes it possible to achieve a reduction in fuel consumption. For the first time, the 911 Carrera models

transmission. Other functions related to the Auto Start Stop system are described in Group 2 (DME).

9_25_11

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also feature the Auto Start Stop function in combination with the 7-speed manual

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9.4 Lighting To ensure good visibility at night and a high level of road safety, the 911 Carrera (991) models are equipped with powerful Bi-Xenon main headlights as well as front light modules with daytime running lights, position lights and direction indicator lights in LED technology. The tail lights are also designed entirely using LED techno-

Electrics and electronics

9

logy.

Light functions Standard equipment: Bi-Xenon (dipped beam)

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Optional: Bi-Xenon with cornering light and PDLS (Porsche Dynamic Light System)

Lamp type D3S (mercury-free) 9_27_11 9_29_11

Figure 9_29_11 shows the LED side marker light in light guide technology.

9_31_11

Figure 9_31_11 shows the LED daytime running light in light guide technology (SMD).

9_30_11

Figure 9_30_11 shows the LED direction indicator.

9_26_11

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Electrics and electronics

9

Porsche Dynamic Light System The PDLS (Porsche Dynamic Light System) optionally available for the 911 Carrera models comprises a swivelling PDLS module for the dynamic cornering light and speed-sensitive headlight range control (AFS). It operates with a projection system (PDLS is active when the light switch is in "AUTO" position).

The projection system includes a rotating drum with various contours for modifying

!

the light/dark border of the light as well as a lens. The headlight can be set to different light modes, e.g. country road light and highway light, by way of the drum and changes in the light output. An adverse weather function will also be implemen-

headlight range control. English defintion

ted for the first time. A halogen auxiliary high beam light is also included in the

is, Adaptive Forward Lighting (In German

PDLS to supplement the Xenon high beam light, which already illuminates the area in

means Automatische Fahrlicht

front of the vehicle particularly effectively due to the drum position with the cover

Steuerung).

open fully and higher light intensity.

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AFS is acronym for speed-sensitive

Light functions (PDLS) Country road light/dipped beam

9_33_11

The country road light/dipped beam of the PDLS ensures better illumination of the surroundings and better range compared with the dipped beam of the previous Bi-Xenon headlight. This is achieved by adapting the light cone by way of a special anti-glare contour in such a way that there is no glare for oncoming traffic.

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Motorway light (2-stage)

Electrics and electronics

9

9_34_11

blinding oncoming traffic. Thanks to adapted light output and distribution, it provides optimum illumination of the road without increasing glare for the traffic in front. It increases the driver's range of vision by up to 164 ft (50 meters) compared with the conventional dipped beam.

The highway light is automatically activated if the vehicle speed exceeds 68 mph (110 km/h) for more than 33 seconds or above 81 mph (130 km/h) without any preconditions. It is switched off immediately without any other conditions at speeds of less than 50 mph (80 km/h). It must be noted that the adapted light distribution of the highway light is not activated due to legal requirements in the USA (and in all countries where headlights Code 553 are installed). Activation of the AFS function highway light takes place in two stages.

Stage 1: Increase in power output of Xenon lamp from 35 W to 37 W and light distribution like for country road light. Stage 1 is activated as from a speed of 56

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The highway light increases the range of vision on multi-lane roads without

mph (90 km/h) after a certain period of straight-ahead driving.

Stage 2: Increase in light distribution with maintained increase in power output.

Stage 2 is activated from 68 mph (110 km/h). Stage 2 is activated immediately as from 81 mph (130 km/h), also without previous activation of stage 1.

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Electrics and electronics

9

High beam, incl. halogen auxiliary high beam light

9_35_11

vehicle. High beam can be activated only if dipped beam is active. The auxiliary high beam light (separate halogen light source) is always activated when high beam is active. The lifting motor (switching shutter) is activated in the case of Bi-Xenon headlights and the drums on AFS headlights.

Adverse weather or fog light function

9_36_11

The adverse weather or fog light function reduces the risk of the driver being blinded in poor weather conditions, e.g. heavy snowfall or fog, by swivelling the left headlight outwards by 8° and setting a horizontal light distribution. The power output is also reduced to 33 W and the cornering light is deactivated. Together, these measures reduce the amount of light reflections, both from the road surface and due to fog. The function is activated when the rear fog light is switched on and at speeds between 6 and 44 mph (10 and 70 km/h).

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High beam is used to extend the illumination range of the road in front of the

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911 Carrera 911 Carrera S

Cornering light Electrics and electronics

9

9_37_11

The light control swivels the headlights to the side by up to 15° (15° for light unit on inside of bend, 7.5° for light unit on outside of bend), depending on the steering angle and vehicle speed in the bend.

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The dynamic cornering light is activated as from a speed of > 2.2 mph (3.6 km/h).

A second cornering light characteristic is available for Sport mode. This function

The light beam is therefore projected onto the road to a maximum range without

can be activated/deactivated by coding

blinding oncoming traffic. Consequently, when driving in the dark on twisting roads,

with the PIWIS Tester II /Codings –

the driver can see which way the road is going and can detect any obstacles much

Adaptations/Customer-specific settings.

earlier and adapt his/her driving style accordingly. This feature also provides a significant increase in safety when driving on country roads and in extended highway

Dynamic cornering light adjustment =

bends by optimally illuminating bends. Sensors continuously measure the driving

15° on inside of bend (green lines) and

speed, lateral acceleration and steering angle, and use this information to calculate

7.5° on outside of bend (red lines).

the bend path. A control unit uses the data it receives to determine the best angle for controlling the dynamic cornering light.

The cornering light also remains active when the high beam is switched on, improving the driver’s visibility.

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Electrics and electronics

9

Tail lights The tail lights are designed completely in LED technology and include a rear fog light. Their very short response times improve active safety. In the event of very heavy braking or an emergency stop, the brake lights flash to warn the following traffic. If the vehicle is braked to a standstill, the hazard warning lights are also activated automatically.

The following lights are designed using LED technology: • Side marker lights (see Fig. 9_38_11) in LED and light guide technology • Brake lights (see Fig. 9_39_11) 9_38_11

• Direction indicators lights with side marker light (see Fig. 9_40_11) in LED

• Back-up light with side marker light (see Fig. 9_41_11)

9_39_11

Rotary light switch The rotary light switch is used to control various light functions: • Switch lights on/off • AUTO= Automatic headlights • Parking light

9_40_11

• Dipped beam/driving light • Rear fog light

9_42_11

Rain function 9_41_11

The headlights are switched on automatically after five seconds of continuous wiper operation. If the wipers have not been used for approx. 4 minutes, the headlights are switched off.

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and light guide technology

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Communication with the front-end electronics takes place via the LIN data bus and a redundant (hard-wired) cable that is directly connected to the front-end electronics and guarantees light functions via the rain-light-moisture sensor in the event of LIN failure.

Electrics and electronics

9

The automatic headlights function (standard equipment) is a new comfort function.

The headlights (dipped beam) are switched on and off automatically depending on the ambient brightness. The automatic headlights function also controls the daytime running lights, dipped beam, automatic Welcome Home lights and equipmentdependent dynamic cornering lights.

The automatic headlights function is activated by setting the light switch to "AUTO"

for the automatic headlights function is accommodated in the mirror base of the interior mirror and automatically switches from daytime running lights to dipped beam when it is getting dark and when driving through tunnels, for example, if the rotary light switch is in "AUTO" position.

The "AUTO" automatic headlights function also activates the automatic Welcome Home function (Coming-home/Leaving-home).

Light design package A light design package (LED light package for the interior) with ambient lighting is optionally available to further enhance comfort and day-to-day usability. As well as adjustable dimmed continuous lighting in the overhead operating console, the package includes additional high-intensity LED orientation lights in the doors (storage compartment lighting), in the rear and in the footwells.

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position. The new automatic headlights function also increases comfort. The sensor

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Electrics and electronics

9

Hazard warning flashing/accident flashing The hazard warning and accident flashing functions are essentially similar. Hazard warning flashing provides a warning around the whole vehicle and is activated manually by way of the hazard warning light button. Accident flashing is activated automatically in the event of a vehicle accident in order to alert other vehicles.

Both functions have priority over the direction indicator function.

In the event of a lamp failure, the flashing frequency of the direction indicator lights does not change. In contrast, the feedback lamps on the instrument cluster and in the hazard warning light button flash much more quickly.

The US variant features flasher repeaters and side marker lights.

The duty cycle is lower for accident flashing than for hazard warning flashing.

again.

9_43_11

Fig. 9_43_11 shows the activated high-level brake light.

Table: Equipment scope of interior lights: LED/incandescent lamps Type

Equipment scope

LED

Interior and reading light in the overhead operating console Orientation light in the overhead operating console Make-up lights in the sun visors Ashtray lighting Ignition lock light

Incandescent lamp

Footwell lighting Glove compartment light Safety and exit lighting Luggage compartment lighting

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Accident flashing can be deactivated by switching the ignition off and then back on

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The front-end electronics control unit communicates with the gateway via CAN Comfort. The front-end electronics control unit includes several function groups and functions. These will be described in more detail below.

9_44_11

Lighting function group The side marker lights, dipped beam, high beam and fog lights are controlled by a rotary light switch which is connected to the front-end electronics via a LIN data bus system and a hard-wired connection. The automatic headlights function (rotary light switch position “1”) allows automatic control of light functions by the front-end electrics electronics control unit. This takes place depending on light and weather conditions. A rain-light-moisture sensor is connected via a LIN bus for detection of the prevailing conditions. Other functions such as the headlight flasher and the various direction indicator functions are controlled by the combined steering column

Electrics and electronics

9 cardiagn.com

9.5 Front-end electronics control unit

9_45_11

module connected to the CAN data bus. The hazard warning light function is activated manually by the hazard warning light button or automatically via a crash signal sent via the CAN data bus (crash flashing).

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Electrics and electronics

9

Other functions/input signals • Rotary light switch (hard-wired/LIN): redundant cable for LIN failure • Hazard warning light button: activation of the hazard warning light function • Rain-light-moisture sensor: activation of automatic functions (light, wipers, ventilation) • Front lid micro switch: opening the luggage compartment lid

Output signals • Fog light FL/FR: signal output for fog light activation • Dipped beam FL/FR: high beam FL/FR, signal output for activation of dipped beam/high beam

• Direction indicator F/R: signal output for activation of direction indicators (all) • Flasher repeaters: signal output for activation • Drum (AFS) L/R: activation of light functions • Light, front luggage compartment lid: signal output for light activation

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• Side marker light FL/FR: signal output for activation of side marker lights

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Access and driving authorization

9

The purpose of this function group is to allow a person with a valid key to enter, start and use the vehicle. The system provides a warning by way of audible and

Electrics and electronics

visual signals in the event of an unauthorized access attempt.

There are two different variants here: 1.)

Basic variant with normal radio remote control

2.)

Enhanced variant Porsche Entry & Drive

Basic variant In the basic variant, the radio key (remote control) is used to open, close, lock (radio interface 433 MHz) and start the vehicle (transponder interface).

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Porsche Entry & Drive Porsche Entry & Drive is offered as an option. Porsche Entry & Drive allows vehicle use without active key handling (radio interface for near-field communication 125 kHz) and can be recognized by the lock buttons in the door handles. The system consists of: • Vehicle transmitter inside the vehicle key

9_46_11

• System comprising interior and external antennas • Proximity sensors in the door handles and front apron • Locking buttons in the exterior door handles

!

Deactivation of the radio receiver after a standing time of one week no longer applies.

2

3

3

2

1

Interior antennas

1

External antennas

2

Proximity sensors

3

1

3

2

9_47_11

On vehicles with Porsche Entry & Drive, the vehicle can be unlocked, locked, started and stopped without using the key. The driver simply has to have the key in their possession. As soon as the driver touches the door handle, Porsche Entry & Drive interrogates an access code that is saved in the key.

9_48_11

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Electrics and electronics

9

If this is correct, the door is unlocked. In the same way, the luggage compartment lid is released and can be opened if the front end is approached. The vehicle is started or stopped using the operating element (dummy) in the electrical ignition starter switch.

To lock the vehicle, one of the locking buttons in one of the door handles or the locking button on the key must be pressed. Porsche Entry & Drive locks the vehicle and activates the steering column lock. If a door or the luggage compartment lid is not completely closed, the vehicle cannot be locked using Entry & Drive. A warning message will then appear on the multi-function display. The key must be outside the vehicle when locking it and within the reception range, otherwise the vehicle doors cannot be locked. If the vehicle key with remote control is out of range, the vehicle

To realize this functionality, the electronics of the radio remote control (radio interface 433 MHz) has been extended by the ID transmitter function (radio 9_49_11

interface/near-field communication). Proximity sensors were integrated into the outer door handles and external antennas in the area of the front end for keyless access with Porsche Entry & Drive. The system detects the user's intention to access the vehicle by means of these proximity sensors and initiates a coded request via the external antennas. If there is an authorized key on the side on which the intention to access has been detected, this receives the request and returns an appropriate, encoded response to the control unit in the vehicle. Following positive authentication of the key, the function (central locking system) is enabled in accordance with the selected setting.

9_50_11 Proximity Sensor

The communication range between the vehicle and key is limited to approx. 5 ft (1.5 m). The key can receive the signal from the external antennas within this range.

When leaving the vehicle, the procedure is analogous to that for accessing it. After closing the doors, the user only needs to press one of the locking buttons in the outside door handles to initiate the request to the externally located key. If this request is correctly answered by the key, the vehicle is locked. To start the vehicle, it is sufficient for the key to be inside the vehicle.

If the operating element in the ignition lock is actuated, the system initiates a request to the key. If the key is inside the vehicle, it detects the request and returns a specific encoded response. Based on this response, the steering column lock is released electronically, the ignition is activated and the engine is started after positive authentication of the engine immobilizer with the engine control (DME). The engine is switched off by moving the operating element (dummy) into the "off" position. The vehicle can also be locked and unlocked in the conventional way by way of the radio remote control or door locking cylinder.

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doors can no longer be opened after they are locked.

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Online engine immobilizer 5 The electronic engine immobilizer 5 (EI) protects the vehicle from unauthorized use.

A 5th generation online engine immobilizer is being used for the 991 Carrera.

Electrics and electronics

This function was integrated in the front-end electronics control unit (master). In order to achieve a higher degree of security, the engine immobilizer is distributed

9

over several components. These include: • Vehicle key with transponder • Front-end electronics control unit (FEE) • Electromechanical steering lock (ESL)

!

• Engine control unit (DME)

The vehicle key includes:

• Alarm system master (rear-end electronics/REE)

Radio interface 433 MHz

Vehicle key with transponder The vehicle key has a radio interface and a transponder interface. The user can actively operate functions of the central locking system via the radio interface, i.e. lock and unlock the vehicle. A transponder interface is used for the function in the ignition lock (engine start/enabling).

The data is exchanged between the key and the ignition lock via this interface.

A battery is not required in the key for this interface. With the "Porsche Entry & Drive" option, the key has an additional radio interface for near-field communication/detection of approach to the vehicle (125 kHz). The central locking system (open/close function) responds via the normal radio interface (433 MHz).

Porsche Entry & Drive

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Transponder interface

9_51_11

9_52_11

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Electrics and electronics

9

Engine immobilizer 5 The front-end electronics control unit (engine immobilizer master) is responsible for deciding when to release the engine immobilizer. All components of the engine immobilizer must be authenticated by the master (FEE) for this purpose. The engine immobilizer master functionality is integrated in the front-end electronics.

Electromechanical steering lock The electromechanical steering lock has the task of blocking the steering by mechanical means in order to prevent unauthorized use of the vehicle. The electromechanical steering lock is installed in the steering system and can only be removed after dismantling the steering system.

steering lock must be authenticated for release of the ignition by the engine 9_53_11

immobilizer master. When the electromechanical steering lock receives the voltage enable signal from the rear-end electronics, it sends the feedback released/locked to the front-end electronics.

Engine control unit (Digital Motor Electronics - DME) The engine control unit is authenticated by the engine immobilizer master via the CAN bus. Since the engine immobilizer master and the engine control unit are not on the same CAN bus, the messages are routed via a gateway. The engine management system is released by the engine control unit as a requirement for engine 9_54_11

operation only after positive authentication.

Rear-end electronics control unit After authentication with the engine immobilizer master, the rear-end electronics enables the power supply for the electric steering lock.The alarm system function is integrated into the rear-end electronics (alarm system master). The same processes that are used to release the engine immobilizer are utilized by the rear end control unit. Deactivation of the alarm system takes place using the same encryption as driver authorization and KESSY.

9_55_11

9_56_11

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As a component of the electronic engine immobilizer, the electromechanical

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Terminal control function group The front-end electronics control unit is responsible for terminal control. The relays of terminals 15 and 50HS (High Side) are connected to the control unit for this purpose.Terminal 15: When the ignition is switched on, a relay (main fuse box/power distributor) switches a voltage to terminal 15.

Electrics and electronics

9

Terminal 50HS: A relay switches terminal 50HS if the clutch is pressed (on vehicles with automatic transmission, brake actuated and selector lever in P or N position) and the switch is then set to "Start" position. The DME provides the starter relay with the terminal 50LS (Low Side) activation signal to activate the relay and the engine starts. The switch automatically returns to "ignition" position again from this position. The engine is switched off by turning the ignition lock (electronic ignition

The ignition key is inserted in the ignition lock below the light switch on the left of the steering wheel. On vehicles with Porsche Entry & Drive, it is no longer necessary to insert the key in the ignition lock. Instead, it is sufficient to carry it on your person. The ignition key is replaced by a control unit in the ignition lock that always remains in the ignition lock unless the vehicle is being towed.

The ignition lock has three key positions. The ignition lock is connected as a LIN slave with the front-end electronics control unit (LIN master).

Data bus systems 3 LIN data bus systems are connected to the front-end electronics control unit with the following function groups.

• LIN 1: Wipers, rotary light switch, rain-light-moisture sensor • LIN 2: Electrically adjustable steering column, Home Link (UGDO) • LIN 3: Electronic ignition lock, electric steering lock

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lock) to "Off" position.

9_57_11

9_58_11

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Electrics and electronics

9

Other functions • Anti-removal lock for ignition lock/P switch • Central locking antenna (windshield - remote control) • Switch/glove compartment light (+) • Washer fluid level sensor • Crash signal (PWM) • Terminal 15 - heated washer jets • Two-tone horn relay • Tank cap actuating element • Dual washer pump f/r

9.6 Rear-end electronics control unit The rear-end electronics control unit communicates with the gateway via CAN Comfort. The rear-end electronics control unit includes several function groups and functions. These will be explained in more detail below.

Lighting function group The daytime running lights (front left/right) are controlled by way of a CAN signal from the front-end electronics control unit. The rear left and right brake lights and the high-level brake light are controlled by a hard-wired signal from the brake light 9_59_11

switch and via a CAN signal (redundant). The back-up lights are activated by a switch on vehicles with manual transmission and by a CAN signal from the selector lever in the case of automatic transmissions. The tail lights, rear fog lights and license plate lighting are also connected to this control unit.

Other lighting functions: • Terminal control G1 (comfort lighting) • Engine compartment light • Luggage tray light • Ambient light (rear interior light left/right) • Door sill lighting

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• Headlight cleaning system

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Access and driving authorization/alarm system The alarm siren is connected via a LIN bus (LIN 2) to the rear-end electronics control unit and triggers an alarm if an attempted theft is detected. The alarm horn is equipment-specific (especially USA) and must be coded in the rear-end electronics control unit. An alarm horn is used for the RoW market which is activated by way of

Electrics and electronics

9

a relay.

The roof module is connected to the rear-end electronics control unit via a LIN bus (LIN 1). It optionally has an integrated inclination sensor (INC) and features radar interior surveillance in all vehicles. Both of these functions can be deactivated as required for certain countries by way of a pushbutton (remote control). If the vehicle is locked and an alarm event is detected by the interior surveillance system

control unit (alarm system master). The externally running sliding roof, air deflector and roll-up sunblind are also controlled via LIN 2.

A breakage sensor for the rear window is achieved utilizing the rear window heating element. If the heater circuit is interrupted when the alarm is activated glass breakage is detected.

Other functional scopes • LEDs front door panels, pushbutton interior surveillance/inclination sensor • Pushbutton/microswitch for front/rear lid • Actuating element for front/rear lid • Exhaust flap control • Rear spoiler relay • Hall-effect sensors for rear spoiler

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or the inclination sensor, the roof console sends a signal to the rear-end electronics

Installation position alarm siren 9_60_11

• Heated rear window relay • Coolant level sensor • Brake pad wear

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Electrics and electronics

9

Data bus systems Two LIN data bus systems are connected to the rear-end electronics control unit with the following function groups: LIN 1: Overhead operating console with inclination sensor, radar interior surveillance, EC interior mirror, externally running sliding roof, air deflector, roll up sunblind LIN 2: Alarm horn

9.7 Instrument cluster The instrument cluster is the central driver information unit and is used to display

levels, warnings and messages.

General vehicle settings can be made in the instrument cluster by way of a selection 9_61_11

menu and made available to the control unit network via CAN. The following vehicle information is displayed in the middle on-board computer display area: Vehicle, Audio, Navigation, Map, Phone, Trip, Tire pressure, Chrono, Gear shift assist, Maximum g-force.

The instrument cluster also manages all on-board computer values, e.g. remaining range, and the warnings and audio information signals for the entire vehicle system. The engine and vehicle speed evaluation function determines the noise level in the passenger compartment so that the warning tone intensity can be adapted correspondingly.

The audio master supports simultaneous output of at least three system tones via 9_63_11

the speaker in the instrument cluster (ParkAssist, direction indicator noise, warning tone).

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data relating to the vehicle, e.g. engine speed, vehicle speed, temperatures and fill

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tachometer. The other dial faces are black.

Electrics and electronics Displays: Description

Tube

Displaytype

Distance, trip mileage

Left

Display

Digital speedometer, upshift indicator

Center

Display

Current gear, transmission position

Center

Display

TFT display; main display with on-board computer, warning master, outside temperature/date, compass, setting menus

Right

Display

Speed display, Speedometer (km/h or mph)

Left

Analog

Sport display (only in digital speedometer)

Center

Digital

Tachometer

Center

Analog

Fuel level

Right

Analog

Coolant temperature

Right

Analog

Oil pressure

Left

Analog

Oil temperature

Left

Analog

Gear Shift Assist

Gear shift assist In order to assist performance-orientated driving, a graphic upshift indicator display is available in the main menu "Gear shift assist".

The segments are colored in the order white, yellow, red.

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In contrast to the Carrera, the Carrera S is provided with a silver dial face on the

9_64_11

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9.8 ParkAssist The 911 Carrera (991) is equipped as standard with a ParkAssist system with 4 ultrasonic sensors at the rear. This system is also optionally available with Topview display (4 sensors at front and 4 at rear) (see Figs. 9_66_11 and 9_67_11). The ultrasonic sensors in the bumpers are used to calculate the distance between an obstacle and the vehicle bumper. This is then indicated to the driver both audibly and visually. The audible indication signals are different for obstacles at the front/rear.

The system performance is designed so that the system does not just permit parking between two vehicles, but also guarantees reliable detection of obstacles with a small reflection area.

dynamic obstacles that could lead to vehicle damage at the front and/or rear.

Warnings are provided by visual displays and acoustic warnings via the speaker in 9_65_11

the instrument cluster.

!

The ultrasonic sensors are powered with a voltage of 12 V. For diagnostic purposes, a piece of foam can be stuck over individual parking sensors. This makes them "blind" and therefore allows isolation of possible sensor faults.

The visual warning is provided by a graphic display (Topview display [see Figs.

9_66_11 and 9_67_11]) on the PCM or CDR and is active after "Ignition on".

9_66_11

The operating range is from 0 mph (0km/h) up to a speed of approximately 9 mph (15 km/h). The tones for the audible warning have a lower pitch at the rear than at the front. The intervals decrease to a continuous tone as the vehicle comes closer to an obstacle. The audible warning at the front starts from 39˝ (100 cm) and at the rear from 47˝ (120 cm). A one-off initial warning tone is issued when an obstacle is detected at a distance of 71˝ (180 cm).

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The basic requirement for the “ParkAssist” system is that it must detect static and

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If the distance to the obstacle does not change, the tone is faded out after approx.

8 seconds. If the vehicle continues to approach the obstacle, the audible warning starts again. In addition, the distances to obstacles are displayed in the form of a schematic representation of the top view of the vehicle in the central display. The visual warning is activated automatically at a distance of 31˝ (80 cm) at the front

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9

and approx. 24˝ (60 cm) at the sides. The visual display is always activated when reverse gear is engaged.

ParkAssist is also activated if the rolls back by approx. 12˝ (30 cm) without reverse gear being engaged. Only audible warnings are provided for obstacle distances at the front between 39˝ (100) and 31˝ (80 cm).

CD radio (CDR) or Porsche Communication Management (PCM). Obstacles at the side of the vehicle are shown as from approx. 24˝ (60 cm) at the front and from approx. 28˝ (70 cm) at the rear. The distance values determined by the system are filtered to achieve a steady and stable display of obstacles. As a result, obstacles are only displayed after approx. 2 seconds when the vehicle is stationary (as opposed to when it is moving). ParkAssist is activated when the ignition is switched on.

ParkAssist can be switched off using the ParkAssist OFF switch in the overhead operating console (LED of the button lights up in this case). ParkAssist remains deactivated until it is switched on again via the button or the ignition is switched off and on again.

ParkAssist is active/in standby mode • When ignition is switched on

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The visual warning can be additionally activated by pressing the CAR button on the

• At vehicle speeds <9 mph (15 km/h), vehicle rolling • EPB not actuated • Reverse gear/transmission range "R" selected

ParkAssist is not active • Ignition off • Vehicle speed > 9 mph (15 km/h) • EPB actuated • Transmission range D • Button in roof console not activated • Function deactivated on CDR 31, PCM 3.1 (visual/audible)

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9.9 Infotainment State-of-the-art audio and communication systems familiar from the Panamera and Cayenne are also available for the 911 Carrera models. These meet the highest technical standards and have been optimized to provide enhanced user friendliness.

The now 7-inch color display of the audio system CDR 31 (standard) and of Porsche Communication Management 3.1 (PCM) (option) is positioned higher up on the dashboard for improved ergonomics compared with the 997 II and features a touchscreen for fast and easy operation. The personalization options in the area of audio and communication have been further extended for the new 911 Carrera models in comparison with the predecessor. For the first time, the Burmester ® High-End Surround Sound System is now also available.

and Aux-In) and CDR (Aux-In). In addition, the telephone module is now compatible with an increased number of mobile phones (SIM Access Profile - SAP/Handsfree Profile - HFP).

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System Bose

9_68_11

System Burmester

9_69_11

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The universal audio interface was assigned as standard to the optional PCM (USB

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CDR 31 audio system The new CDR 31 audio system (standard) features a very high-quality user interface.

The look, feel and main functions correspond to the latest PCM generation. The

Electrics and electronics

main feature of the new audio system generation is a 7-inch thick film transistor (TFT) display with touchscreen. All the functions of the CDR 31 system (except for

9

volume) can be selected by touching the color screen. This allows fast and simple navigation through the various menus. In addition, the new display guarantees excellent readability and clarity.

The user interface is adapted to suit the new color screen - both the operating structure and the screen design are the same as for PCM. The screen display is very clear thanks to the fact that a number of functions that are rarely used have been moved to the second menu level ("OPTION"). A maximum of 5 easy-to-read list

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entries are displayed on each page. Activating functions via the touchscreen will be the preferred mode of operation for the majority of customers. Nevertheless, virtually all functions can still be operated in the conventional way using the right rotary/pushbutton switch, depending on individual user preference.

The standard CDR 31 already has a sound system with 9 speakers divided into 7

9_70_11

channels with a total output of 235 W and can be used to play audio CDs and music in MP3 format (formats: mp3, aac, wma). For radio listeners, there are up to 36 memory locations available. 30 locations can be freely assigned, while 6 presets are automatically assigned at regular intervals by the Best FM function of the CDR 31 system to the stations with the best reception.

The standard universal audio interface (glove compartment) allows connection of an external audio source via the AUX interface. Operation takes place directly on the connected device. There is a 12 V plug socket in the glove compartment for supplying power to the external audio source.

9_71_11

CDR 31 audio interface: - Connection of external players via 3.5 mm stereo jack - Operation takes place on the player self - The player battery is not charged

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Porsche Communication Management 3.1 The new generation of the Porsche Communication Management (PCM) incl. navigation module is optionally available. The main new features of the latest generation of PCM compared with the predecessor are: • High-resolution 7-inch WVGA (Wide Video Graphics Array) screen • 3D navigation map with City and Terrain models with superimposed satellite map • Lane information display at complex junctions • Speed limit display in PCM based on navigation data • Map display in the instrument cluster

With the navigation function, users have the option of switching the map view between the new 3D representation (Terrain and City models) or the familiar perspective or two-dimensional representations. The 3D Terrain model with 9_73_11

superimposed satellite map permits an even more detailed and realistic representation.

A speed limit display function shows any speed limits that apply on the roads recorded in the navigation system on the PCM (Car display) or on the TFT display in the instrument cluster. The availability of the speed limit display depends on the relevant database status of the map material (see PIWIS information system for version status).

The navigation module has an integrated hard drive for fast route calculation. Three alternative route suggestions can be displayed for selection in each case.

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• Aux-In and USB connection as standard

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The familiar universal audio interface has been assigned as standard to the PCM option and also permits digital audio transmission with higher sound quality in combination with an iPod®. In general, the universal audio interface makes it possible to connect an external audio source such as an iPod ® or a USB stick.

2 connection points are provided for this purpose in the glove compartment:

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1. In combination with the PCM, it is possible to use the USB connection to connect various iPod® and iPhone® models as well as USB memory sticks with MP3 music or MP3 players. Operation takes place via the PCM, the optional multi-function steering wheel or the optional voice control. The audio data is now transmitted to PCM in digital format instead of the analog format used in the previous model. Digital audio transmission means much higher sound quality in

operation feature in PCM. Access to all track and playback lists has also been made much faster and enables even faster music searches. The standard Apple iPod® USB cable (Apple scope of delivery) is used as the connecting cable; the previous serial cable has been deleted. This USB connection also ensures simultaneous charging of the iPod®.

2. Other external audio sources can be connected via an AUX interface. Operation takes place directly on the connected device.

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conjunction with the iPod. A further advantage is the noticeably faster list

9_75_11

9_76_11

9_77_11

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Infotainment system options The telephone module offers superior operating comfort and optimized voice quality. As a quad-band telephone module (for GSM 800, 900, 1,800 and 1,900 networks), it now covers all common GSM frequency ranges currently used worldwide. In addition to operation with an inserted SIM card, the telephone module can automatically detect the Bluetooth® mobile phone profiles SIM Access Profile (SAP) and Handsfree Profile (HFP) and switch between the modes. The telephone module in the 911 Carrera models can also be optionally ordered with a cordless Bluetooth® handset.

A charging cradle for the cordless handset is available in the storage bin in the

mobile phones with the Hands-Free Profile (HFP) and only wish to use the basic mobile phone functions can also choose the mobile phone preparation as an alternative to the telephone module for PCM. The function for audio transmission via Bluetooth® is available for the first time both with the telephone module and with the mobile phone preparation. This allows audio data to be transferred from external devices such as music players or mobile phones via the Bluetooth ® interface of PCM or internet radio received if this function is supported by the 9_80_11

device connected via Bluetooth®.

Optional: Telephone module

A 6-disc CD/DVD autochanger integrated into the PCM system is also optionally

Mobile phone preparation (CDR 31)

available instead of the single CD/DVD drive. As with the CDR 31 audio system, the

6-disc CD/DVD autochanger

optional digital satellite radio SDARS available in the USA and Canada from the

SDARS (USA/Canada)

provider XM is also available in combination with PCM. In conjunction with PCM, the

El. logbook

traffic information sent by XM can now additionally be taken into consideration

Voice control

during dynamic route guidance. Furthermore, extended data services for weather,

TV tuner

sport and stock market information are also available. Weather information can additionally be displayed in the map in conjunction with the optional XM Nav Weather function. The electronic logbook is also available. This permits automatic recording of current mileage, trip distance, date and time as well as the starting point and destination for each trip. The data can be exported by way of a USB stick and evaluated conveniently with the supplied PC software. A latest-generation voice control system is available in conjunction with the new hard drive navigation system.

With this system, the voice inputs for the city and road are evaluated together to increase unambiguity. This two-list matching method simplifies operation compared with the previous two-stage successive evaluation and at the same time increases the probability of immediate recognition of the sought address. This ensures relaxing operating comfort while driving. The driver's hands can stay on the steering wheel and their eyes can stay on the road.

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center console. Analogously to the CDR 31 audio system, customers who have

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An SDARS (Satellite Digital Audio Radio Services) antenna is used for North America. A GPS antenna is connected to the PCM for receiving navigation signals (interior mirror base on windshield, see Fig. 9_86_11, red area). A mobile radio antenna is connected for receiving mobile phone signals (GSM) in combination with the built-in telephone module (interior mirror base on windshield, see Fig. 9_86_11,

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9

blue area).

Microphones In order to permit use of the phone function, one microphone is connected to the CDR 31 head unit and two microphones to the PCM 3.1 for the hands-free function (see Fig. 9_87_11).

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9_86_11

9_87_11

Two microphones are used for voice control (see Fig. 9_88_11, red areas).

9_88_11

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Sound systems The 911 Carrera models offer a superior sound experience as standard with the Sound Package Plus. With 9 speakers divided into 7 channels as well as an external amplifier, a total output of 235 W is offered in a high quality standard. The integrated CD/DVD drive supports audio playback of audio and video DVDs and plays music in MP3 format (formats: MP3, AAC, WMA, WAV).

9_89a_11 9_90_11

254

1

2

3+5

4

Mid-range speaker

Tweeter

Mid-range speaker

Bass speaker

80 mm

19 mm

100 mm

200 mm

4 ohm

4 ohm

4 ohm

4 ohm

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25 W

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BOSE® Surround Sound System The optional BOSE® Surround Sound System comprises a total of 12 speakers, including a 100 W active subwoofer integrated in the bodyshell with output stage and 200 mm diaphragm diameter as well as 8 amplifier channels to provide an impressive sound experience (amplifier, see Fig. 9_91_11). A total output of 445 W

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is therefore available. A frequency range from 40 Hz to 20 kHz is available at every seat; the maximum undistorted continuous sound pressure level for music signals is greater than 115 dB. In combination with PCM, the system now opens up the impressive audio spectrum of digital 5.1 recordings when playing music from audio

9_90_11

or video DVDs. The audio experience is the next best thing to a live performance with sound similar to what you get from a sophisticated home cinema system. In

system is immediately recognizable by the BOSE® logo on selected speakers.

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conjunction with the CDR 31 system, sound reproduction is always in stereo. The

9_91_11

Micro

25 W

9_92_11

1

2+5

3+6

4

7

Mid-range

Tweeter

Mid-range

Bass speaker

Subwoofer

speaker

speaker

80 mm

19 mm

100 mm

220 mm

130 mm

4 ohm

4 ohm

2 ohm

1 ohm

4 ohm

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Burmester® High-End Surround Sound System The Burmester® High-End Surround Sound System was specially adapted for the new 911 Carrera models. 12 individually controlled speakers including an active bodyshell subwoofer with 140 mm diaphragm diameter and integrated 300 W output stage (amplifier, see Fig. 9_89_11), 12 amplifier channels and a total output of more than 800 W. The acoustically effective diaphragm area is over 1,340 cm 2.

A frequency range from 35 Hz to 20 kHz is available at every seat; the maximum undistorted continuous sound pressure level for music signals is greater than 120 dB. In combination with PCM, the Burmester® High-End Surround Sound

9_94_11

System naturally also reproduces digital 5.1 recordings when playing back music from audio or video DVDs. In combination with the CDR 31 system, sound

proven technologies from the Burmester® home hi-fi area ensures "best in class" sound quality in the entire signal chain. Three central goals can be achieved through the consistent use of glass fiber diaphragms in the mid-tone range: glass fiber is lighter than conventional paper diaphragms, enables more stable oscillations through its greater rigidity and leads to an undistorted sound through its higher internal damping. In a fully-active system, every speaker has its own amplifier and maximum signal processing capabilities. Optimal acoustic adaptation of the speakers to the vehicle environment guarantees uniquely balanced, realistic music playback.

9_89_11

The AMT tweeter (Air Motion Transformer ribbon tweeter) uses a folded sheet as the diaphragm. The extremely small vibrating mass with an unrivalled, large diaphragm area produces extremely precise, clean and clear high-frequency sound from very low up to extremely high volumes. A further highlight is the use of specific, suitable filter technologies. Digital FIR filters (Finite Impulse Response) are available, while in the mid- and high-frequency range, additional analog filters with selected precise-tolerance components are used. These are optimized for the relevant application to guarantee the highest level of resolution and best possible pulse reproduction over the entire transmission range.

9_95_11

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reproduction is always in stereo. The consistent use of high quality materials and

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Electrics and electronics Micro

9

9_96_11

2

3+6

4

Mid-range

Tweeter

Mid-range

Bass speaker Tweeter

speaker

5

7 Subwoofer

speaker

80 mm

AMT

100 mm

220 mm

25 mm

2 ohm

6 ohm

2 ohm

1 ohm

4 ohm

In order to meet the requirements of the new 911 models, the Burmester ® High-End Surround Sound System was designed for maximum sound performance with low system weight. This intelligent lightweight design can be seen in the consistent use of highly efficient, particularly light Neodym® magnet material, die-cast aluminum speaker baskets and light plastic composite materials. Despite the outstanding performance on offer, it was possible to achieve an extraordinarily low system weight of just 6.5 kg.

In addition to the usual sound adjustments, i.e. treble, bass, balance and fade,

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various sound presets are also available for the Burmester ® High-End Surround Sound System in conjunction with the CDR 31 audio system and PCM. Sound and technology are not the only areas of excellence offered by the Burmester ® High-End Surround Sound System: its design also meets the highest standards.

Externally, the system is recognizable by its discreet, plated trims with metal surface and Burmester® logos on selected speaker covers. The unique sound and high-quality design of the Burmester® High-End Surround Sound System are therefore the perfect match for the new 911 Carrera models.

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Active subwoofer The highlight of the optional BOSE and Burmester sound systems is the use of the patented bodyshell-integrated subwoofer solution. This development replaces the previous separate subwoofer boxes and uses the vehicle’s body structures. This solution saves 9-11 lbs (4-5 kg) system weight and reduces the installation space

9_97_11

The excellent "driving point" (i.e. the position of the subwoofer in relation to the vehicle geometry) also results in very high system efficiency. The efficiency is up to 10 dB higher than for previous solutions (compared with previous systems, this represents doubling of the volume while at the same time reducing the power consumption by 90 %). The symmetrical arrangement of the cowl panel frame in driving direction with the corresponding sound outlets results in a very uniform bass distribution in the cabin for the driver and passenger with only one speaker chassis.

The design of the bodyshell-integrated subwoofer has been chosen specifically to achieve optimum bass addition in combination with the door woofers. In conventional systems, the parallel arrangement of the two door woofers results in an unavoidable sound cancellation in the upper bass range due to the design restrictions of these systems. This gap in the transmission function is closed by the bodyshell integrated subwoofer.

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required, as well as improving the bass performance at the same time.

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Part Number - PNA 911 021 12