Instrument Lighting

Instrument Lighting

Fault symptoms
Instrument lighting inoperative.

Diagnostic help
Information on the rheostat setting, cabin brightness and display lighting intensity comes from the SID. The MIU uses the information to control the brightness of the instrument lighting, warning and indicator lamps, and the display lighting.

Check the wiring harness
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic tool during the test.

Diagnostic procedure

1. Checking the instrument lighting
- Contact Main instrument unit.






- Activate: Instrument lighting (Main instrument unit): 100%.
- 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
- Use the lights switch to turn on the parking lights or headlamps.






- Cover the photosensor on SID.






- Alter the rheostat.






- Read value: Instrument lighting.
- Reading should be: about 25-99% (according to rheostat setting).

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

3. Final check
- Clear the diagnostic trouble codes in all systems.






- Perform a functional test.






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