FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Faulty Signal






Faulty signal

Checking the connectors




- Ignition off
- Check the brake control module (BCM) and pedal position sensor connectors. Check for contact resistance and oxidation
- Reinstall the components, reconnect the connectors etc.
- Connect the breakout box to the brake control module (BCM)
- Ignition on
- Read off the position and speed of the pedal position sensor.
Depress the brake pedal. Check that the signals are updated.
The signal for the pedal position sensor must increase as the brake pedal is pressed further.
Press the brake pedal at different speeds. Check that the speed signal is updated.

Other information
- To connect the breakout box, see Connecting the breakout box, brake control module (BCM) Connecting the Breakout Box, Brake Control Module (BCM)
- Checking wiring and terminals Checking Wiring And Terminals













Was the signal updated?

Yes - Fault Found

No - Checking wiring and sensors

-------------------------------------------------

Checking wiring and sensors




- Ignition off.
Check the wiring between pedal position sensor
- terminal #1 and control module terminal #7 (#A7)
- terminal #2 and control module terminal #5 (#A5)
- terminal #3 and control module terminal #3 (#A3).
Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.

Hint: Check the pedal position sensor as follows
- ignition off
- connect the breakout box to the wiring
- control module disconnected
measure the resistance at the pedal position sensor.

The resistance between breakout box terminals #3 (#A3) and #5 (#A5) must be approximately 0.5 kohms when the brake pedal is unaffected. The resistance must increase when the brake pedal is pressed.

The resistance between breakout box terminals #3 (#A3) and #7 (#A7) must be approximately 2.5 kohms when the brake pedal is unaffected. The resistance must decrease when the brake pedal is pressed.

Remedy as necessary.

Other information
- To connect the breakout box, see Connecting the breakout box, brake control module (BCM) Connecting the Breakout Box, Brake Control Module (BCM)
- To replace the pedal position sensor, see Pedal sensor power brake booster, replacing Service and Repair
- For information about signals, see Signal specification, brake control module (BCM) with STC/ TRACS Signal Specification and Signal specification, brake control module (BCM) with DSTC (dynamic stability and traction control) Signal Specification
- Checking wiring and terminals Checking Wiring And Terminals













Was a fault detected?

Yes - Verification

No - Fault-tracing information

-------------------------------------------------

Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off
- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Read off the signal from the pedal position sensor.
Depress the brake pedal. Check that the signal is updated.
The signal must increase as the brake pedal is pressed further. Depress the brake pedal at different speeds. Check that the signal is updated.





Was the signal updated?

Yes - Fault Found

No - Fault-tracing information

-------------------------------------------------

Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

------------------------

FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the connectors

-------------------------------------------------




Information

Fault-tracing information
The fault should be diagnosed and remedied. Since this is not the case the fault-tracing process has failed.
Complete the fault-tracing for those fault or try again.

Do you want to terminate fault-tracing at this time?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

------------------------

Attempt New Test - Checking the connectors

FAULT-TRACING FAILED - FAULT-TRACING FAILED

-------------------------------------------------