Operation CHARM: Car repair manuals for everyone.

Signal Missing






Signal missing. Permanent fault

Checking the connectors




- Ignition off
- Check the control module for the steering wheel angle sensor and the steering wheel module (SWM) connectors. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Read off diagnostic trouble codes (DTCs).
If the diagnostic trouble code (DTC) displays an intermittent status, the cause of the fault was probably contact resistance or oxidation in the connector for the control module for the steering wheel angle sensor or in the steering wheel module (SWM).

Other information:
- To disconnect the control module for the steering wheel angle sensor, see Steering wheel module (SWM), replacing Service and Repair
- To disconnect the steering wheel module (SWM), see Steering wheel module (SWM), replacing Service and Repair
- For information about signals for the control module for the steering wheel angle sensor, see Signal description, Control unit for the steering wheel angle sensor (SAS) Signal Specification
- For information about signals to the steering wheel module (SWM), see Signal specification Signal Specification, Steering Wheel Module (SWM).









Does the diagnostic trouble code (DTC) display an intermittent fault?

Yes - Fault Found

No - Checking wiring and sensors

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Checking wiring and sensors








- Ignition off
- The control module for the steering wheel angle sensor disconnected
- Steering wheel module (SWM) disconnected
- Connect the breakout box to the control module for the steering wheel angle sensor and to the steering wheel module (SWM)
Check the wiring between the control module for the steering wheel angle sensor terminal #7 (#A31) and steering wheel module (SWM) terminal #14 (#A14). Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the wiring between the control module for the steering wheel angle sensor
terminal #9 (terminal (#A33) and steering wheel module (SWM) terminal #12 (terminal #A12)
terminal #8 (terminal (#A32) and steering wheel module (SWM) terminal #7 (terminal #A7)
check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Try replacing the steering wheel angle sensor if no fault is found in the wiring.

Other information:
- To connect the breakout box to the control module for the steering wheel angle sensor, see Connecting the breakout box to the steering angle sensor Connecting the Breakout Box, Steering Wheel Angle Sensor Module (SAS)
- To connect the breakout box to the steering wheel module (SWM), see Connecting the breakout box Connecting the Breakout Box, Steering Wheel Module (SWM)
- To replace the steering wheel angle sensor, see Contact reel / steering wheel angle sensor, replacing Contact Reel / Steering Wheel Angle Sensor, Replacing
- For information about signals for the control module for the steering wheel angle sensor, see Signal description, Control unit for the steering wheel angle sensor (SAS) Signal Specification
- For information about signals to the steering wheel module (SWM), see Signal specification Signal Specification, Steering Wheel Module (SWM).










Continue - Verification

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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.
- Read off steering wheel angle signal A.
- Turn the steering wheel to full lock in both directions.
The value should change between OFF and ON.





Does the value change?

Yes - VERIFIED

No - VERIFICATION FAILEDPAPER

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VERIFIED - Fault Found

VERIFICATION FAILED - Fault-tracing information

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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

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the connectors

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