Inspection Procedure 5: The rear fog lamp indicator does not illuminate normally.


caution
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)

COMMENTS ON TROUBLE SYMPTOM


If the rear fog lamp indicator does not illuminate normally, connector(s), wiring harness in the CAN bus lines, the ETACS-ECU or the combination meter may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Check the rear fog lamp


When the rear fog lamp switch is operated, check that the rear fog lamps illuminate/go off normally.

Q. Is the check result normal?

Go to Step 2.

First, repair the rear fog lamp (Refer to trouble symptom chart ).

STEP 2. M.U.T.-III CAN bus diagnostics


Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 3.

Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).

STEP 3. M.U.T.-III diagnosis code


Check if diagnosis code is set to the ETACS-ECU.

Q. Is the diagnosis code set?

Troubleshoot the ETACS-ECU. Refer to .

Go to Step 4.

STEP 4. M.U.T.-III other system special function


Using M.U.T.-III, select "Test" from the special function of the combination meter. Execute the following item to check the rear fog lamp indicator. (Refer to Combination Meter )

Q. Is the check result normal?

Go to Step 5.

Troubleshoot the combination meter. Refer to .

STEP 5. Retest the system


Check that the rear fog lamp indicator illuminate normally.

Q. 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.