Inspection Procedure A-1: When the ignition switch is at the LOCK (OFF) position, the functions do not work normally. Check the battery power supply circuit to the ETACS-ECU.


caution Whenever the ECU is replaced, ensure that the power supply circuit and the earthing circuit are normal.

COMMENTS ON TROUBLE SYMPTOM
If this circuit is defective and the ignition switch is at the LOCK (OFF) position, the ETACS-ECU does not work. In this case, the functions below will be suspended.

  • Lamp reminder function
  • Keyless entry system
  • Ignition key cylinder illumination lamp
  • Interior lamps
However, when the ignition switch is at the ON position, the functions below will work.

  • Reading diagnosis code and checking input signal by M.U.T.-III.
  • Central door locking
  • Headlamp and tail lamp
  • Hazard warning lamp

PROBABLE CAUSES

  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. ECU check by using the SWS monitor
Check that the power supply and earth lines to the ETACS-ECU and the SWS communication lines are normal.

  • Ignition switch: OFF
ECU TO BE CHECKED
  • ETACS ECU
OK: "OK" is displayed on the "ETACS ECU" menu.

Q. Is the check result normal?
Go to Step 2.
Refer to GROUP 54C - Inspection Procedure 2 "Communication with the ETACS-ECU is not possible ."

STEP 2. Retest the system.
Check that the battery power supply circuit to the ETACS-ECU is normal.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).
Replace the ETACS-ECU.