Unreasonable Signal

Unreasonable signal

Checking the connectors




- Ignition off.
- Check the connectors of the ABS control unit and the side acceleration sensor for contact resistance and oxidation, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Connect the connectors, install the components, etc.
- Ignition on.
- Read off the current value.
The value should be approximately 2.5 V.

Additional information:
- For disconnection of the control unit, see Replacing the control module for ABS and dynamic stability and traction control (DSTC) Replacing the Control Module for ABS and Dynamic Stability and Traction Control (DSTC).
- For disconnection of the side acceleration sensor, see Replacing the yaw rate sensor (1) and the lateral acceleration sensor in the center console (DSTC) Service and Repair.
- For information on signals, see Signal specification, ABS / DSTC (dynamic stability and traction control) control module Signal Specification.









Is the value OK?

Yes - Fault Found

No - Checking the wiring and sensor

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Checking the wiring and sensor




- Ignition off.
Check the connectors and the side acceleration sensor for damage. Check also that the side acceleration sensor is correctly fitted and that the bracket is attached properly.

Hint: With the ignition on, check the side acceleration sensor by testing the side acceleration sensor signal between:
- #9 and #40 on the test box. The voltage should be approximately 2.5 V.
- #9 and #25 on the test box. The voltage should be approximately 5 V.

Do the necessary corrective action.

Additional information:
- To connect the test box, see Connecting the ABS/DSTC breakout box Pinout Values and Diagnostic Parameters.
- To replace the side acceleration sensor, see Replacing the yaw rate sensor (1) and the lateral acceleration sensor in the center console (DSTC) Service and Repair.
- For information on signals, see Signal specification, ABS / DSTC (dynamic stability and traction control) control module Signal Specification.













Is there a fault?

Yes - Verification

No - No Fault Found

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Verification




Verification

Verification

Hint: After the repair it is necessary to check that the fault has been rectified.








- Ignition off.
- Connect the connectors, install the components, etc.
- Ignition on.
- Check that the ABS warning lamp lights and goes out after approximately 2 seconds. If the lamp does not go out, the fault has not been rectified.
- Test-drive the car as described in Test driving Test Driving.
Check the ABS warning lamp during the test drive. If the warning lamp lights, return to the workshop and read the diagnostic trouble codes.





Does the lamp go out and stay out?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - Fault Found

VERIFICATION FAILED - Trouble-shooting information

PAPER - No Fault Found

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Trouble-shooting 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

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the connectors

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