Checking The Function Of The Rheostat, Audio HU1205

Checking the function of the rheostat, Audio HU1205

Checking rheostat function




- Ignition on
- Turn the light switch to the half strength setting.
Check that the lighting for the audio unit is working and that the luminance can be controlled with the rheostat control.

Hint: Check the function of the rheostat in other systems such as the climate control module and the combined instrument panel. There is a fault in the central electronic module if the rheostat is not working in any of the systems.









Is the function OK?

Yes - No Fault Found

No - Checking the connectors and cables

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Checking the connectors and cables




- Ignition off.
Check audio unit connector A and rheostat connectors B2. Check for loose connections, contact resistance and oxidation.
Check the signal cables between audio unit terminal #A3 (#17 on the breakout box) and rheostat terminal #B2/23. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.

Hint: If no fault is found above, fault-trace other systems in the car.

Remedy as necessary.

Other information:
- To connect the breakout box, see Connecting the breakout box, Audio HU1205 (audio module) Connecting The Breakout Box, Audio HU1205 (Audio Module)
- For information about signals, see Signal specification Audio HU1205 (audio module) Pinout Values and Diagnostic Parameters
- Checking wiring and terminals Checking Wiring And Terminals.









Continue - Verification

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Verification








- Ignition off
- Reinstall the connectors, components etc.
- Ignition on
- Turn the light switch to the half strength setting.
Check that the lighting for the audio unit is working and that the luminance can be controlled with the rheostat control.
The fault has been remedied if the function is OK.





Is the function OK?

Yes - FAULT FOUND

No - 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 - Exit fault-tracing

No - Attempt New Test

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Attempt New Test - Checking rheostat function

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