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Inspection Procedure 2: The rear dome light does not illuminate normally.
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
OPERATION
The ETACS-ECU illuminates and extinguishes the rear dome light in accordance with the input signals below.
  • Ignition switch (IG1)
  • Key reminder switch
  • Door switches
  • Front door lock actuator (driver’s side)
 
 
TECHNICAL DESCRIPTION (COMMENT)
If this does not work normally, the above switch input circuit(s), rear dome light, or ETACS-ECU may have a problem.
 
 
TROUBLESHOOTING HINTS
  • The key reminder switch may be defective
  • The door switch may be defective
  • The front door lock actuator (driver’s side) may be defective
  • The rear dome light may be defective
  • The ETACS-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:
  • MB992006: Extra fine probe
  • MB991223: Harness set
STEP 1. Front dome light operation check.
Check that the front dome light illuminates and extinguishes normally.
Is the check result normal?
Go to Step 2.
Refer to Inspection Procedure 1 "The front dome light does not illuminate normally." .
 
STEP 2. Rear dome light bulb check.
Check that the rear dome light bulb is normal.
Is the check result normal?
Go to Step 3.
Replace the rear dome light bulb.
 
STEP 3. Check of open or short to ground circuit in LP+1 line between the rear dome light connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of open or short to ground circuit in RLP- line between the rear dome light connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 5. Check of open circuit in ground line between the rear dome light connector and body ground.
Is the check result normal?
Replace the rear dome light, and then go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Retest the system.
Check that the rear dome light illuminates/extinguishes normally.
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 ETACS-ECU.