[Previous][Next]
Inspection Procedure 4: Audio illumination does not work normally.
 
 
cautionBefore replacing the radio and CD player, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
TECHNICAL DESCRIPTION (COMMENT)
If the taillights illuminate, illumination signal is sent from the heater controller assembly (A/C-ECU) to the radio and CD player. This switches the illumination of the radio and CD player from day mode to night mode. If the mode is switched, the illumination signal line, the heater controller assembly (A/C-ECU) or the radio and CD player may be defective.
 
 
 
TROUBLESHOOTING HINTS
  • The combination meter may be defective
  • The heater controller assembly (A/C-ECU) may be defective
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
 
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check that the taillights illuminate.
Is the check result normal?
Go to Step 2.
Diagnose the taillights. (Refer to .)
 
STEP 2. Check the illumination.
When the taillights are turned on, check whether the illumination other than the radio and CD player is turned on.
Is the check result normal?
Go to Step 3.
Replace the heater controller assembly (A/C-ECU).
 
STEP 3. Check of short to power supply, short to ground, and open circuit in ILL+ line between radio and CD player connector and heater controller assembly (A/C-ECU) connector
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Retest the system
When the taillights illuminate, check that the illumination of the radio and CD player is switched from day mode to night mode.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the radio and CD player.