Center display unit does not dim

NOTE: 

• Check the vehicle 12 volt battery condition first .
• Turn the headlight on, and check that the dash brightness setting is not set to high.
• 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. Check the illumination of the center display unit screen and buttons.

   Does the center 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 (interior lights circuit, others)

   -1. Check the illumination of several other buttons not related to the audio/navigation system.

   Are the buttons illuminated?

   YES 

   Go to step 3.

   NO 

   Troubleshoot the interior lights.

3. Open wire check (ILLUMI+ line)

   -1. Turn the combination light switch off.

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

   -3. Disconnect the following connector.

   Center display unit connector A (5P)

   -4. Turn the combination lighting switch to the parking light ( ) position.

   -5. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Center display unit connector A (5P): disconnected
   Test point 1	Center display unit connector A (5P) No. 3
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   Replace the center display unit .

   NO 

   Repair an open in the wire between the center display unit and the taillight relay.