Audio System Symptom Troubleshooting - Audio unit button illumination does not work
Audio unit button illumination does not work
NOTE:
Check the vehicle 12 volt battery condition first.
Check for B-CAN DTCs and resolve them before troubleshooting.
Check the connectors for poor connections or loose terminals.
1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Turn the combination light switch to the parking light (enu_255699_1.0) position.

?3.
Check the illumination of the audio unit buttons.

Are the buttons illuminated?

     
YES
     
     
     
Intermittent failure, the audio unit is OK at this time.?
     
NO
     
     
     
The failure is duplicated, go to step 2.
2.
Determine possible failure area (interior lights circuit, others):

Determine possible failure area (interior lights circuit, others)
?1.
Check the illumination of several other buttons not related to the audio system.

Are the buttons illuminated?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Troubleshoot the interior lights.?
3.
Determine possible failure area (audio unit, others):

Determine possible failure area (audio unit, others)
?1.
Go into the System Diagnostic Mode, and use the ILLUMI in the Vehicle Information to check the ILLUMI signal.

Does the METER_ILL STATUS signal change from [0] to [1] when the combination light switch is turned to the parking light position?

     
YES
     
     
     
     
NO
     
     
     
Go to step 4.
4.
Open wire check (B-CAN_H line, B-CAN_L line):

Open wire check (B-CAN_H line, B-CAN_L line)
?1.
Turn the combination light switch off.

?2.
Turn the vehicle to the OFF (LOCK) mode.

?3.
Disconnect the following connectors.
Gauge control module 32P connector
Audio unit connector C (24P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Gauge control module 32P connector: disconnected
 
Audio unit connector C (24P): disconnected
Test point 1
Gauge control module 32P connector No. 23
Test point 2
Audio unit connector C (24P) No. 24


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
Repair an open in the wire(s) between the audio unit and the gauge control module.?