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 for B-CAN DTCs and resolve them before troubleshooting.
• Check the connectors for poor connections or loose terminals.

• 1. Problem verification:

  - 1. Turn the vehicle to the ON mode.

  - 2. Turn the combination light switch to the parking light position.

  - 3. Rotate the dashlights brightness controller knob several times.

  Does the multi-information display brightness change?

  YES 

  Intermittent failure, the system is OK at this time.

  NO 

  The failure is duplicated, go to step 2.

• 2. 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.

  Multi-information display unit connector A (32P)

  Gauge control module connector A (32P)

  - 4. Check for continuity between test points 1 and 2.

  Test condition	Vehicle OFF (LOCK) mode
  	Multi-information display unit connector A (32P): disconnected
  	Gauge control module connector A (32P): disconnected
  Test point 1	Multi-information display unit connector A (32P) No. 31
  Test point 2	Gauge control module connector A (32P) No. 30

  Test point 1	Multi-information display unit connector A (32P) No. 15
  Test point 2	Gauge control module connector A (32P) No. 31

  Is there continuity?

  YES 

  Replace the multi-information display unit .

  NO 

  Repair an open in the wire(s) between the multi-information display unit and the gauge control module.