Points to remember
- Observe the test conditions. Use common sense in assessing the readings.
- The test readings presented are taken with the ignition switched ON unless otherwise stated.
- Start by checking that the control module is receiving power and is grounded.
- Check all sensor inputs and signals from other systems.
- Finally, check the control module outputs. Remember that the readings do not provide an indication that the actuator is operating.
- If any reading is not OK, consult the wiring diagram to trace the leads, connectors or components that need further checking.
- The specified readings are valid for a correctly calibrated Fluke 88/97.
- The readings %(+) and ms(+) indicate the pulse ratio and pulse length. A test instrument capable of measuring both pulse ratio and pulse length must be used. The '+' sign denotes a positive trigger pulse (TRIG+).
Scheme 197
Note. A BOB cable assembly has not been produced for ESP. Unless otherwise stated, the test readings are those that should be obtained on the control module connector (unplugged).
> = greater than; < = less than; ~ = alternating current (LP: LOGIC PROBE P = select pulse; p = visible pulse)
| Pin | Component/function | In/Out | Test conditions | Test across | Test reading | See |
|---|---|---|---|---|---|---|
| 1 | Pump motor, power ground | In | B+ - 4 | B+ | See RETURN PUMP | |
| 2 | +30 voltage, power | IN | 2 - B | B+ | See POWER SUPPLY | |
| 3 | Current (+30 circuit) | IN | 3 - B | B+ | See POWER SUPPLY | |
| 4 | Ground | IN | B+ - 4 | B+ | See CONTROL MODULE GROUND | |
| 5 | Wheel sensor, FL: signal input | IN | Rotate the wheel one turn per second | 5 - 6 | >100 mV AC | See SPEED SENSOR, FRONT WHEEL |
| 6 | Wheel sensor, FL: reference ground | IN | Rotate the wheel one turn per second | 5 - 6 | >100 mV AC | See SPEED SENSOR, FRONT WHEEL |
| 7 | Wheel sensor, RL: signal input | IN | Rotate the wheel one turn per second | 7 - 27 | >100 mV AC | See SPEED SENSOR, REAR WHEEL |
| 8 | Wheel sensor, RR: reference ground | IN | Rotate the wheel one turn per second | 29 - 8 | >100 mV AC | See SPEED SENSOR, REAR WHEEL |
| 9 | Wheel sensor, FR: reference ground | IN | Rotate the wheel one turn per second | 10 - 9 | >100 mV AC | See SPEED SENSOR, FRONT WHEEL |
| 10 | Wheel sensor, FR: signal input | IN | Rotate the wheel one turn per second | 10 - 9 | >100 mV AC | See SPEED SENSOR, FRONT WHEEL |
| 11 | Data link | IN/OUT | Tech 2 not connected | 11- - B | 0 V | |
| Tech 2 connected and ESP selected for communication | 11 - B | Variable, approx. 10V | ||||
| 12 | Spare | |||||
| 13 | Spare | |||||
| 14 | P-bus | Bus information | 14 - 4 | Approx. 2.5V | ||
| 15 | System ground for yaw rate sensor | Cannot be measured | ||||
| 16 | Yaw rate sensor, yaw rate signal | IN | Cannot be measured | See YAW RATE SENSOR (658) | ||
| 17 | Spare | |||||
| 18 | Yaw rate sensor, reference signal | OUT | Cannot be measured | See YAW RATE SENSOR (658) | ||
| 19 | Signal from wheel sensor, rear left Used by special equipment | OUT | Cannot be measured | |||
| 20 | Lateral acceleration sensor, lateral acceleration | IN | Cannot be measured | See YAW RATE SENSOR (658) | ||
| 21 | Spare | |||||
| 22 | Spare | |||||
| 23 | Spare | |||||
| 24 | Spare | |||||
| 25 | Spare | |||||
| 26 | Spare | |||||
| 27 | Wheel sensor, RL: reference ground | IN | Rotate the wheel one turn per second | 7 - 27 | >100 mV AC | See SPEED SENSOR, REAR WHEEL |
| 28 | Current (+15 circuit) | IN | 28 - B | B+ | See POWER SUPPLY | |
| 29 | Wheel sensor, RR: signal input | IN | Rotate the wheel one turn per second | 29 - 8 | >100 mV AC | See SPEED SENSOR, REAR WHEEL |
| 30 | Brake Light Switch | IN | Brake pedal depressed | 30 - B | B+ | See BRAKE LIGHT SWITCH |
| Brake pedal released | 30 - B | 0 V | ||||
| 31 | ESP ON/OFF switch | IN | Switch not depressed | B+ - 31 | 0 V | See ESP ON/OFF SWITCH |
| Switch depressed | B+ - 31 | B+ | ||||
| 32 | Spare | |||||
| 33 | Spare | |||||
| 34 | Spare | |||||
| 35 | P-bus + | Bus information | 35 - 4 | Approx. 2.5V | ||
| 36 | Spare | |||||
| 37 | Yaw rate sensor, reference signal | OUT | Cannot be measured | See YAW RATE SENSOR (658) | ||
| 38 | Spare | |||||
| 39 | Spare | |||||
| 40 | Signal from wheel sensor, front right, for PSG16 | Cannot be measured | ||||
| 41-45 | Spare | |||||
COMPONENT FUNCTION - TEST CONDITIONS
Scheme 198
See SERVICE MANUAL 1:4 TECH2
Group: Test equipment
| 9000 | 900-M93 | 900/9-3 | 9-5 | 9-3 (9440) |
|---|---|---|---|---|
| X | X | X | X | X |
SPECIAL TOOLS REFERENCE
Scheme 199
Group: Test equipment
| 9000 | 900-M93 | 900/9-3 | 9-5 |
|---|---|---|---|
| X | X | X | X |
SPECIAL TOOLS REFERENCE
Scheme 200
Voltage range 8-16V
Group: Test equipment
| 9000 | 900-M93 | 900/9-3 | 9-5 | 9-3 (9440) |
|---|---|---|---|---|
| X | X | X | X | X |
SPECIAL TOOLS REFERENCE
Scheme 201
Bleeding brake and clutch systems
Group: Chassis
| 9000 | 900-M93 | 900/9-3 | 9-5 | 9-3 (9440) |
|---|---|---|---|---|
| X | X | X | X | X |
SPECIAL TOOLS REFERENCE
When the control module is supplied with current, the processor in it is tripped. The processor then reads the instructions stored in the control module's memory.
The control module is programmed to read the inputs and activate the outputs. If the control module program is faulty, the diagnostic trouble code "Internal Control Module Fault" will be generated.
The control module must be supplied with current before the system will function. The control module is supplied with current and the processor tripped when the control module can be contacted by the diagnostics instrument.