Inspection Procedure 1: None of the tail lamps illuminate.

  • 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 .)


If all the tail lamps do not illuminate normally, the tail lamp switch input circuit or ETACS-ECU may have a problem.



STEP 1. Licence plate lamp operation check

Check that the licence plate lamp illuminates normally.

Q. Is the check result normal?

Go to Step 2.

Replace the ETACS-ECU.

STEP 2. 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 3.

STEP 3. M.U.T.-III data list

Use the ETACS-ECU service data to check the signals related to the tail lamp illumination.

Item No.
Item name
Normal condition
Item 340
Head lamp switch (tail)
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 4.

Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 11 "The column switch signal is not received" .

STEP 4. Retest the system

Check that the tail lamp illuminates 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.