Caterpillar Machine Electronics Course Manual – PDF DOWNLOAD

Caterpillar Machine Electronics Course

© 2006 Caterpillar Inc.

BASIC ELECTRICAL CIRCUIT ELEMENTS

Ground

Source

Protection

Control

Load

Ground

ELECTRICAL PARAMETERS - Voltage: Pressure that moves the current - Current: Movement of electrons in a circuit - Resistance: Opposition to current flow

OHMS LAW SOLVING CIRCLE

E I

R

SOLVING FOR UNKNOWN VOLTAGE

E

E 6A 2

E=IxR E = 6A x 2 E = 12V

I

R

SOLVING FOR UNKNOWN RESISTANCE

12V

E

6A ?

E = 12V I = 6A R=2

I E R= I

R

SOLVING FOR UNKNOWN CURRENT

12V

E ?A 2

E = 12V I = 6A R=2

I

R E I= R

SERIES CIRCUIT Fuse

+

-

Voltage is the SUM of all voltage drops.

Current is the SAME at any given point in the circuit.

Resistance is the SUM of all individual resistances.

SERIES CIRCUIT

TOTAL RESISTANCE

VOLTAGE AND RESISTANCE GIVEN 3

3 R = R1 + R2 + R3 t

R1 -

+

12V

+

-

R2 R3

6

R =3 t

+3

+6

R = 12 t

12V

CURRENT FLOW I = E/R I = 24V/12 I = 2 Amps

VOLTAGE DROP E = I/R E1 = 2A x 3

= 6V

E2 = 2A x 3

= 6V

E3 = 2A x 6

= 12V

PARALLEL CIRCUIT Fuse

+

-

PARALLEL CIRCUIT VOLTAGE AND RESISTANCE GIVEN

1 1 1 1 + + Re = R1 R2 R3

Fuse

+

-

+

SOLVING FOR TOTAL RESISTANCE IN A PARALLEL CIRCUIT

-

4 ohms

4 ohms

24V

Re =

Re =

1 1 1 + 4 4 1 1 2

or

1 .50

Re = 2 ohms

CURRENT FLOW IN EACH BRANCH

I = E/R I = 24/4 I = 6 amps (in each branch)

TOTAL CURRENT FLOW

6 amps + 6 amps = 12 amps

SERIES-PARALLEL CIRCUIT

R1

+

12V

R2

R3

SERIES-PARALLEL CIRCUIT RESISTANCE VALUES 2

Solve for the Parallel

R1

Equivalent Resistance (Re)

-

+ 12V

R2

6

R3

1 1 1 + = Re R2 R3

3

EQUIVALENT SERIES CIRCUIT 2

1 Re =

1 (.1666) + 1 (.3333) 6 3

R1 +

1 = .50 Re Re = 2

12V

R2

Equivalent Resistance

Re 2

R3

TOTAL CIRCUIT RESISTANCE

EQUIVALENT SERIES CIRCUIT 2 R1 +

Rt = R1 + Re

12V

R2

Re 2

Rt = 2

R3

+2

=4

Equivalent Resistance

TOTAL CIRCUIT CURRENT

SERIES PARALLEL CIRCUIT ALL VALUES 6V 3A 2

I = E/R R1

I = 12/4 = 3 amps

-

+ 12V

R2

6V 1A 6

R3

6V 2A 3

BASIC ELECTRONIC SIGNALS - DC Signals - AC Signals - Voltage - Current

SIGNAL MODULATION - Analog (Voltage Level) - Frequency - Pulse Width Modulation (PWM) - Represented as Duty Cycle

Fixed Positive

Fixed Negative 0

+12V

7V 6V

-6V 7V

0

+

Time (A)

Varying Positive

-12V

Time (B)

+12V

DC SIGNALS

Positive Pulse

6V

0

0 Time (C)

Time (D)

One Hertz

SINE WAVES

0

Time

+

Peak Voltage

RMS Voltage

.707 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

SINE WAVES

0

.707 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Time

ANALOG SIGNALS DC Volts

+

0 Pressure ( kPa)

DIGITAL SIGNALS High

Two Distinct

Low

Amplitude Levels

PULSE WIDTH MODULATED "DUTY CYCLE" TIME ON vs TIME OFF +

On

0 Off

One Period

INPUT DEVICES - Switches - Senders - Sensors

SWITCHES (ON / OFF INPUT DEVICES) Parameter Monitored Temperature

Switch Makeup Variable Input with Thermistor or Thermocouple Strain Gauge with Variable Resistor and Switch

Pressure Bellows w/Induction or Capacitor and Switch Fluid Flow Coolant Level

Operator Activated

Paddle with Switch Variable Resistor with Switch - Toggle - Push / Pull - Momentary (Hold) - Push to Set / Push to Release

BRAKE OIL TEMPERATURE SWITCH

REAR BRAKE OIL TEMPERATURE SWITCH CIRCUIT

Main Display Module Ground

2

Rear Brake Oil Temperature

29

GN 16 BK 16

1 2

BK 18 BK 18 T Rear Brake Oil Temperature Switch

DMM MEASUREMENTS - Volts - Ohms

BRAKE OIL PRESSURE SWITCH

DMM MEASUREMENTS BRAKE OIL PRESSURE SWITCH CIRCUIT Main Display Module Ground

2

Brake Oil Pressure

20

BK 16 PK 16

C B A

- Volts

BU 16 RD 16 BK 16 Brake Oil Pressure Switch

- Ohms

FLUID FLOW SWITCH - Paddle with Switch

DMM MEASUREMENTS COOLANT FLOW SWITCH CIRCUIT

Engine ECM Ground

2

Coolant Flow

18

BU 16 BK 16

1 2

BK 18 BK 18

Coolant Flow Switch

- Volts - Ohms

ENGINE COOLANT LEVEL SWITCH - Variable Resistor with Switch

DMM MEASUREMENTS

COOLANT LEVEL SWITCH CIRCUIT Engine ECM

J2

+8V

2

Ground

3

Coolant Level

24

WH 18 GR 18 GY 18

A B C

OR 18 YL 18 GN 18

+8v Ground Signal Coolant Level Switch

- Volts - Ohms

OPERATOR ACTIVATED SWITCHES - Toggle - Push / Pull - Momentary (Hold) - Push to Set / Push to Release

DMM MEASUREMENTS

PARKING BRAKE SWITCH CIRCUIT Transmission E CM

J1

Sensor Ground Return

12

Parking Brake Op Switch

44

BN 16 PK 16

1 2 3 4

- Volts Parking Brake Switch

- Ohms

SENDERS / SENSORS (VARIABLE INPUT DEVICES) Parameter Monitored Speed

Sensor Makeup Pickup Coil

DMM Active or Measurements Passive Passive (2 Wire) Volts / Hz / Ohms

Hall Effect

Active (3 Wire)

Variable Resistor

Passive (2 Wire) Volts / Ohms Active (3 Wire) Volts / Ohms Active (3 Wire) Volts / Hz / Duty Cycle

Volts / Hz / Duty Cycle

Temperature

Variable Resistor Variable Resistor

Pressure

Strain Gauge with Variable Resistor

Active (3 Wire)

Volts

Active (3 Wire)

Volts / Hz / Duty Cycle

Variable Resistor

Active (3 Wire)

Hall Effect

Active (3 Wire)

Magnetoresistive

Active (3 Wire)

Variable Resistor

Passive (2 Wire) Volts / Ohms

Ultrasonic

Active (4 Wire)

Position

Fuel Level

Volts / Hz / Duty Cycle

Volts / Hz / Duty Cycle

PASSIVE SPEED SENSORS - 2-Wire Sensor - Magnetic Pickup Coil

DMM MEASUREMENTS - Volts - Hz - Ohms

ACTIVE SPEED SENSORS - 3 Wire Sensor - Hall-Effect

DMM MEASUREMENTS

SPEED SENSOR CIRCUIT Engine ECM

J1

+V Sensor Supply

11

Sensor Ground Return

12

Engine Speed

62

OR 18 BR 18 YL 18

A B C

OR 18 BK 18 YL 18

+V Ground Signal Engine Speed Sensor

- Volts - Duty Cycle

PASSIVE TEMPERATURE SENSORS - 2-Wire Sensors - Variable Resistor

Engine ECM

J2

Temp Sensor Common

18

PK 18

Coolant Temp Sensor

32

BU 18

1 2

COOLANT TEMPERATURE SENSOR CIRCUIT

Coolant Temp Sensor

DMM MEASUREMENTS - Volts - Ohms

DIGITAL PRESSURE AND TEMPERATURE SENSORS - 3 Wire Sensors - PWM

TRANSMISSION OIL TEMPERATURE SENSOR CIRCUIT 725 / 730 / 735 ONLY Transmission E CM

J1

+8v Sensor Supply

11

Sensor Ground Return

12

Transmission Oil Temp Sensor

52

OR 18 BR 18 PK 18

A B C

+8v Ground Signal

Transmission Oil Temperature Sensor

DMM MEASUREMENTS - Volts - Hz - Duty Cycle

DIGITAL TEMPERATURE SENSOR

V+ +8

B+ Gnd Signal

A B C

DIGITAL TEMPERATURE SENSOR Electronic Control Sensor Supply

Oscillator

Duty Cycle

A C Signal Amplifier Thermistor

B

Ground

ANALOG PRESSURE AND TEMPERATURE SENSORS - 3-Wire Sensors - Variable Resistor

OIL PRESSURE SENSOR CIRCUIT Engine ECM

J2

Pressure Sensor +5V

2

Pressure Sensor Common

3

Oil Pressure

24

DMM MEASUREMENTS WH 18 GR 18 GY 18

A B C

OR 18 YL 18 GN 18

+5V Ground Signal Oil Pressure Sensor

- Volts

ANALOG TEMPERATURE SENSOR Engine Control

Thermistor

T

Amplifier

A

5V

C

Signal (0 - 5V)

B

Analog Return

ANALOG TO DIGITAL SENSOR Analog Section

Digital Converter

PWM Output To Control

Signal V+ Ground

Schematic Envelope

Display Graphics

FUEL LEVEL SENDER RESISTIVE

DMM MEASUREMENTS FUEL LEVEL SENDER CIRCUIT Fuel Level Sender

Main Display Module Fuel Level Sender

9

PK 16

- Volts

PK 18

- Ohms

FUEL LEVEL SENSOR ULTRASONIC

DMM MEASUREMENTS

FUEL LEVEL SENSOR CIRCUIT

Main Display Module

J1

Sensor Ground

26

Sensor Ground

12

Fuel Level

44

Keyswitch

46

OR 18 BK 18 BU 18 YL 18

1 2 3 4

+ Battery Ground Signal Deep Signal Shallow Fuel Level Sensor

- Volts - Hz - Duty Cycle

POSITION SENSOR - 3-Wire Sensor - PWM - Variable Resistor

THROTTLE POSITION SENSOR CIRCUIT Engine ECM

J1

Digital Sensor Power +8V

4

Digital Sensor Return

5

Throttle Sensor

66

GR 18 BR 18 OR 18

A B C

RD 18 BK 18 YL 18

+8V Ground Signal

Throttle Sensor

POSITION SENSOR - 4-Wire Sensor - PWM - Hall-effect

SHIFT LEVER POSITION SENSOR CIRCUIT From +24v Ignition Transmission ECM

J1

YL 16 BR 16

Shift Lever Sensor

26

Sensor Ground Return

12

PU 16

1 2 3 4

+Battery Ground Signal Cal

Shift Lever Sensor

ECM +5 Volts (Pull-up Voltage)

To Input Device

Signal Sensing Circuit

ECM +5 Volts (Pull-up Voltage)

0V

Input Device

5V

Signal Sensing Circuit

ECM +5 Volts (Pull-up Voltage)

5V

Input Device

0V

Signal Sensing Circuit

PULL-UP VOLTAGE TEST Measure between Pins B (Ground) and C (Signal) with Sensor Connected to Obtain Sensor Signal Voltage Measure between Pins B (Ground) and C (Signal) with Sensor Disconnected to Obtain Pull-up Voltage

ELECTRONIC CONTROL MODULE SIGNAL PROCESSING Microprocessor

Initial Signal Conditioning

Switches Senders Sensors

Switches Senders Sensors

Actuator Power Switch

Digital Input Signal

Power Switch

Protective Circuit

Analog Input Signal Protective Circuit

Digital Signal Processing Amplifier, Filter

A/D Converter

Power-gain Amplifier D/A Converter Power-gain Amplifier

Solenoids Lamps Horns

CATERPILLAR ECMs ECM Type

Applications

ADEM

Engine

MAC

Machine Systems

ABL

Machine Systems

A4

Multiple Applications

ECM DIAGNOSIS - Check Diagnostic Codes - Check Input Power - Check Ground - Check Power Supplies to Sensors - Check Communication with Cat ET - Use Validator ECM - Call Dealer Solutions Network - Call ECM Hotline

7 9 7 B ELECTRONIC SYSTEMS Monit oring

VIMS

VIMS-PC

12

mph Km/ h

3F VIMS ABL2 M

Et Service Tool

RS2 3 2 Link

ADEM II Mast er

ADEM II Slave 1

ATA Dat a Link ADEM II Slave 2

CAT Dat a Link

Gauges Monit oring Prognost ics Warnings Telemet ry Payload Measurement Clock Synchronizat ion Machine ID Aut o-lube

Engine Slaves

Mast er

CAN SAE J1 9 3 9 Dat alink

-

-

Throt t le Posit ion Throt t le Bypass Engine Speed Manual St art Aid Pre-lubricat ion

-

Emission Cont rol Engine Shut downs Fuel Inject ion Et her Inject ion Engine Speed Diagnost ics

Transmission ABL2 C

Chassis -

Neut ral St art Back-up Alarm Load Count er Body Up Gear Limit

-

St art er Prot ect ion Hoist Cont rol Reverse Neut ralizer Accumulat or Bleed

Brake / Cooling ABL2 C -

Aut o Ret arder Cont rol ( ARC) Tract ion Cont rol Syst em ( TCS) Parking Brakes Engine Fan Speed Cont rol Brake Cooling Pump Speed Cont rol Brake Temp Monit oring Rear Axle Cooling and Pressure Cont rol

Abl2 c

-

Elect ronic Clut ch Pressure Cont rol ( ECPC) Fail in Gear Prot ect ion Neut ral Coast Inhibit Cont rol Throt t le Shift ing ( CTS) Direct ional Shift Management Overspeed Prot ect ion - Torque Limit ing Speed Limit er - Top Gear Limit

- Tire Monit or (Fut ure)

- Road Analysis Cont rol ( RAC)

DATA LINK FAULTS - Opens, Shorts, High Resistance - Use Digital Multimeter to Test for: - Data Communications Activity - Circuit Faults

OUTPUT COMPONENTS - Solenoids - Relays - Lamps / Indicators - Alarms - Digital Displays - Motors

Test Port

Ball

Spring

Valve Spool

Orifice

Spring

IMPELLER CLUTCH SOLENOID ENERGIZED Solenoid

Armature Assembly

From Pump

To Impeller Clutch Test Port

Ball

Spring

Valve Spool

Orifice

Test Port

Solenoid

Armature Assembly To Impeller Clutch

Spring

IMPELLER CLUTCH SOLENOID DE-ENERGIZED From Pump

Test Port

Ball

Valve Spool

Orifice

Spring

LOCKUP CLUTCH SOLENOID ENERGIZED Solenoid

Pin

From Pump To Lockup Clutch Test Port

Ball

Valve Spool

Orifice

Spring

LOCKUP CLUTCH SOLENOID DE-ENERGIZED Solenoid

Pin

From Pump To Lockup Clutch

PROPORTIONAL SOLENOID INPUT CURRENT VERSUS PILOT PRESSURE

PWM SOLENOID ELECTRO-HYDRAULIC IMPLEMENT SYSTEM

Pilot Pressure (psi)

600 500 400 300 200 100 0 0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Solenoid Current (Amps)

PILOT CONTROL ACTUATORS HOLD Centering Springs

Stabilizing Spring

Actuator Solenoid

Pilot Spool

Feedback Spring

Main Spool

Spring Retainer

Pilot Oil Port

Tank Oil Port

Actuator Solenoid

0.8

0.9

1.0

1

5

PWM SOLENOID

D10R TRANSMISSION CONTROL GROUP

ELECTRO-HYDRAULIC TRANSMISSION

2

3

4

TRANSMISSION MODULATION CYCLE

TRANSMISSION MODULATING VALVE Shaft

Ball

Reducing Spool

Orifice

Pressure and Current

Solenoid

Pilot Valve

Fill Pulse

Fill Calibration Parameters

Engagement Calibration Parameters

Clutch Engagement Level Maximum Clutch Pressure

Ramp Level Modulation

Hold Level

To Drain

5

To Clutch

3

Supply Oil Pulse Delay

Pulse Time

Ramp Time

Hold Time Approx. 1 Second

Desired Slip Time

Full On Time

PWM SOLENOID ELECTRONIC UNIT INJECTOR (EUI)

Pull-in Peak Current

Current Flow

Hold-in Peak Current

0

1

2

3

Time (Milliseconds)

4

5

+Batt Control Signal

High Current

Start Relay Starter Solenoid

Key Start Switch +Batt +

_ Battery

Alert Indicator

Engine Temp 60 Deg F

[135]

SERVICE INFORMATION - Troubleshooting Manuals - Electrical Schematics

ENGINE TROUBLESHOOTING MANUALS - Electronic Troubleshooting - Programming Parameters - Troubleshooting w/o Diagnostic Code - Troubleshooting with Diagnostic Code - Functional Tests - Calibration Procedures

MACHINE TROUBLESHOOTING MANUALS - Systems Operation - Troubleshooting - Testing and Adjusting

ELECTRICAL SCHEMATIC SYMBOLS Pos

Neg

10 A

Motor

Solenoid

Motor

T

Disconnect Switch

Transistor

Battery

Circuit Breaker

Fuse

Light

T

Temperature Switch

Pressure Switches

Toggle Switch

T

Reostat

Resistors

Potentiometer

Resistor G

Ign

Alt +

R

Mtr

Bat

Send Motor

Grd

Alternator

S

Gauge

Relay

Ground

Starter

FRONT OF SCHEMATIC - Color codes for circuit identification - Color abbreviation codes - Symbol descriptions - Wiring harness information - Schematic notes and conditions - Grid design for component location - Component part numbers

DASHED LINES - Colored - Heavy and double-dashed - Thin black dashed

WIRE IDENTIFICATION LABELS OLD FORMAT Color Code

Wire Size

Wire Label

169 - PK - 18

NEW FORMAT Wire Label

Color Code Wire Size

169 - H5 PK - 18 Wire No. 5 in Harness "H"

CONNECTOR IDENTIFICATION .

OLD FORMAT Connector Label

Connector Label

H G

Connector Label

NEW FORMAT H-C7 1552267

"H" is the harness identification, "C" stands for connector, "7" is the connector number in the harness, and P/N is the receptacle connector part number

COMPONENTS OLD FORMAT FUSE P/N 10 A

NEW FORMAT H-P12 113-8490 10 A

SPLICES OLD FORMAT 10 A

405-GY-16 Splice

405-GY-18

NEW FORMAT 10 A

405-G9 GY-16 Splice 405-G7 GY-18 Splice 405-G14 GY-18

BACK OF SCHEMATIC - Schematic symbols - Wire description chart - Related electrical service manuals - Harness connector and component locations - Switch, resistor, and solenoid specifications - Diagnostic code list

WIRE GAUGE AWG

DIAMETER (Circular mils)

10 12 14 16 18 20 22 30 40

102.9 80.8 64.1 50.8 40.3 32.0 25.4 10.0 3.10

OHMS PER 1000 FT .9989 1.588 2.525 4.016 6.385 10.15 16.14 103.2 1049.0

CONNECTOR ASPERITY No Asperity

Asperity Contact

Pin Contacts Socket

Asperity in Pin Contacts Socket

Pin

Condition of Asperity Contact

No Contact

Electrons Converging

No Contact

TYPES OF CONNECTORS - VE Connectors - Sure-Seal Connectors - Deutsch Connectors

MONITORING SYSTEMS - Caterpillar Monitoring System - Navigator Monitoring System - Vital Information Display System (VIDS) - Vital Information Management System (VIMS)

CATERPILLAR MONITORING SYSTEM BLOCK DIAGRAM Speedometer/ Tachometer Module

Gauge Cluster Module

12

Mph Km/h

Main Display Module

Action Lamp

c KpaMiles Km rpm Liter Serv Code X10

3f

. . .

Action Alarm

Input Components

Display Data Link Cat Data Link

Transmission ECM

Implement ECM

Engine ECM Input Components

Input Components

Input Components

MODES OF OPERATION Mode of Operation Normal Service Meter Odometer Tachometer Diagnostic Scrolling Harness Code Numeric Readout Service Tattletale Units Setup Calibration

Mode Number 0 * * * * 1 * * * * * *

Available as Operator Mode Yes Yes Yes Yes Yes No No No No No No No

*Check the appropriate machine electrical schematic for specific machine mode numbers.

SERVICE MODE

30 110F08

SERV CODE

SERV CODE

VITAL INFORMATION MANAGEMENT SYSTEM (VIMS) COMPONENT DIAGRAM

Gauge Cluster Module

Service Lamp

Speedometer/ Tachometer Module

Message Center Module

Keypad Module Ok 0 1

Service Key Start Switch

VIMS RS-232 Port

12

Main Module

3f

VIMS Service Tool and Software

VIMS Interface Module

ID DEF

2

3

JKL

MNO

4

5

6

PRS

TUV

WXY

7

8

9

P1

P2

P3

Cat ET Display Data Link

VIMS

mph Km/h

ABC

GHI

VIMS Interface Module

Keypad Data Link Cat Data Link Engine Control

Action Alarm Action Lamp Cat Data Link Sensors

Sensors Sensors

Implement Control

Transmission Control

MESSAGE CENTER MODULE Data Logger Indicator

Alert Indicator

Universal Gauge

ENGINE TEMP 60 Deg F

[135]

Gauge Warning Area Message Area

MESSAGE CENTER AND KEYPAD

ENGINE TEMP 60 Deg F

OK

[135]

ABC

DEF

GH1

JKL

MNO

PRS

TUV

WXY

F1

F2

F3

ID

DATA EVENTS

OIL PRESSURE CALL SHOP

ERROR

EVENT DIAGNOSTIC CODE

OIL PRESSURE ERROR MID057 CID0827 FMI100

USING A TROUBLESHOOTING PROCESS - Understand the strategy - Visualize where you are in the process - Know the resources available - Use critical thinking skills - Have system knowledge - Have tools and test procedure knowledge

TROUBLESHOOTING PROCESS STEPS 1. Isolate the problem 2. Use available resources 3. List possible faults 4. Test faults and determine cause 5. Repair 6. Verify repair 7. Document repair

OPERATOR INTERVIEW - How long?

- Adjustments or repairs?

- Worse under Load?

- Noises?

- Weather?

- Intermittent?

VISUAL INSPECTION - Check for Alert Indicators and Warning - Check Wiring and Connections - Check Linkages and Components

REVIEW SERVICE INFORMATION - Check for Service Codes - Review Operation and Maintenance Manuals - Review Electrical Schematic - Check Other Service Literature

INTERMITTENT ELECTRICAL FAULTS - Check that connectors mate properly - Check that wires are secure in connector and crimped - Check wires for nicks or abrasions in insulation - Check for moisture at the connector - Check the contacts for dirt or corrosion - Perform a pull test

DIGITAL MULTIMETER