Auto Start Stop function

DME engine electronics 2

2_476_11

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 switched off • All functions keep working

Operating principle

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.

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

• Press the button. • The indicator light in the button comes on. • Automatic stopping of the engine is suppressed and coasting mode is deactivated.

Activating

• 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. DME engine electronics 2

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.

Prerequisites for the automatic engine stop

• 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.

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

Vehicles with manual transmission:

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):

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

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. DME engine electronics 2

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.

DME engine electronics 2

Diagnostic options for the Auto Start Stop function using the PIWIS Tester, for example: • DME actual values: ST010 to ST320 • Drive links • Guided Fault Finding 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 engine is automatically stopped.

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. • If the charge state of the battery is low. • On uphill or downhill gradients. • When vehicle-internal test processes are taking place, for example automatic 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.