Instrument Lighting Not Working

Instrument Lighting Not Working

Fault symptoms
Instrument lighting not working.

Diagnostic help
The lighting can be activated with the diagnostic instrument.

Information on the instrument lighting comes from SID.

Checking the wiring harness
Jiggle the leads and in-line connectors at various points and in different directions to detect any intermittent breaks or short circuits in the wiring. Observe the multimeter, test lamp or diagnostic instrument while carrying out this check.

Diagnostic procedure

1. Checking the instrument lighting
^ Check the lamps by activating the instrument lighting with the diagnostic tool.





^ All the lamps should light up.





Is the function correct?
YES
^ Go to step 2.
NO
^ Replace the faulty bulb.
^ Go to step 3.

2. Checking SID
^ Switch on the parking lights or headlamps.
^ Cover the photosensor on SID.





^ Alter the rheostat.





^ Read the instrument lighting value in the MIU with the diagnostic tool.





^ The value should change.

Is the function correct?
YES
^ Go to step 3.
No
^ Continue with fault diagnosis of SID.

3. Final check
^ Clear diagnostic trouble codes in all systems.





^ Carry out a function check.





Is the function correct?
YES
^ The steps taken to rectify the fault were correct.
NO
^ See Fault diagnosis, general, "Before changing a control module." Before Changing A Control Module