Audio System Symptom Troubleshooting - Display does not dim or brighten with dimmer
Display does not dim or brighten with dimmer
NOTE:
Check the vehicle 12 volt battery condition first.
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 lighting switch to the parking light (enu_255699_1.0) position.

?3.
Rotate the Select/Reset knob several times.

Does the audio unit display brightness change?

     
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 (ILLUMI CANCEL line, others):

Determine possible failure area (ILLUMI CANCEL line, others)
?1.
Turn the combination light switch off.

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

?3.
Disconnect the following connector.
Gauge control module 32P connector

?4.
Turn the vehicle to the ON mode.

?5.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Gauge control module 32P connector: disconnected
Test point 1
Gauge control module 32P connector No. 9
Test point 2
Body ground

Is there about 3.0 V?

     
YES
     
     
     
The ILLUMI CANCEL wire is OK. Go to step 3.
     
NO
     
     
     
Go to step 4.
3.
Gauge control module check:

Gauge control module check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Reconnect the gauge control module 32P connector.

?3.
Turn the vehicle to the ON mode.

?4.
Turn the combination lighting switch to the parking light position.

?5.
Rotate the Select/Reset knob to the left to select the dimming mode.

?6.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Gauge control module 32P connector No. 9
Test point 2
Body ground

Is there less than 0.2 V?

     
YES
     
     
     
     
NO
     
     
     
4.
Open wire check (ILLUMI CANCEL line):

Open wire check (ILLUMI CANCEL line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Gauge control module 32P connector: disconnected
Test point 1
Audio unit connector A (24P) No. 2
Test point 2
Body ground

Is there about 3.0 V?

     
YES
     
     
     
Repair an open in the wire between the audio unit and the gauge control module.?
     
NO
     
     
     
The ILLUMI CANCEL wire is not open. Go to step 5.
5.
Shorted wire check (ILLUMI CANCEL line):

Shorted wire check (ILLUMI CANCEL line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
NOTE: Eject the disc before disconnecting the audio unit to prevent damaging the CD player's load mechanism.

Audio unit connector A (24P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Gauge control module 32P connector: disconnected
 
Audio unit connector A (24P): disconnected
Test point 1
Audio unit connector A (24P) No. 4
Test point 2
Body ground

Is there continuity?

     
NO
     
     
     
Repair a short to body ground in the wire between the audio unit and the gauge control module.?
     
YES