Troubleshooting
Troubleshooting
Checking brake control module (BCM) and wheel sensor's connector
- Ignition off
- Check the connectors of the brake control module (BCM) and the wheel sensors for contact resistance and oxidation.
- Reinstall the components, reconnect the connectors etc.
- Lift the vehicle so that the wheel in question hangs freely.
- Ignition on
- Read off the speed for the wheel in question.
Rotate the wheel in question and check that wheel speed is updated.
If wheel speed is updated, the malfunction was caused by poor contact in the control module's or wheel sensor's connector.
Note! The wheel signal will only be active for approx. 20 seconds. Activate the service again if necessary.
Other information
- Disconnecting the brake control module's connector: Connecting the breakout box, brake control module (BCM), B6324S5 Connecting The Breakout Box
- Disconnecting the wheel sensor's connector: Wheel sensor front, replacing Wheel Sensor, Front, Replacing
- Checking wiring and terminals Checking Wiring And Terminals
Is wheel speed updated?
Yes - FAULT FOUND
No - Checking wiring and sensors
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Checking wiring and sensors
Checking the voltage feed
Check the signal cable for open circuit, short circuit to ground and short circuit to supply voltage.
Measure between:
- Brake control module (BCM) terminal #45 (#A45) (front left) and terminal #1 of the relevant sensor.
- Brake control module (BCM) terminal #34 (#A34) (front right) and terminal #1 of the relevant sensor.
Checking the signal cable
Check the signal cable for open circuit, short circuit to ground and short circuit to supply voltage.
Measure between:
- Brake control module (BCM) terminal #46 (#A46) (front left) and terminal #2 of the relevant sensor.
- Brake control module (BCM) terminal #33 (#A33) (front right) and terminal #2 of the relevant sensor.
Checking sensor function
With the sensor connected and the ignition on, check the sensor by connecting a breakout box and measuring the signal from the sensor.
Measure on the breakout box between:
- #45 (#A45) and #46 (#A46) (front left).
- #34 (#A34) and #33 (#A33) (front right).
Voltage should vary approx. 1 V when the toothed wheel rotates. If voltage is incorrect, replace the wheel sensor.
Remedy as necessary.
Other information
- Connecting the breakout box, brake control module (BCM), B6324S5 Connecting The Breakout Box
- Signal specification, brake control module (BCM) with STC/ TRACS, B6324S5 Signal Specification, Brake Control Module (BCM) With STC/ TRACS
- Signal specification, brake control module (BCM) with DSTC (dynamic stability and traction control), B6324S5 Signal Specification, Brake Control Module (BCM) With DSTC (Dynamic Stability And Traction Control)
- Wheel sensor front, replacing Wheel Sensor, Front, Replacing
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the malfunction has been remedied.
- Ignition off
- Reinstall the components, reconnect the connectors etc.
- Lift the vehicle so that the wheel in question hangs freely.
- Ignition on
- Read off the speed of the wheel in question.
Rotate the wheel and check that wheel speed is updated.
Note! The wheel signal will only be active for approx. 20 seconds. Activate the service again if necessary.
Is wheel speed updated?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - Troubleshooting information
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Troubleshooting 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 - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking brake control module (BCM) and wheel sensor's connector
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