INSPECTION PROCEDURE A-1: Central Door Locking System does not work at All.


caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.






OPERATION


If the input signals from the front door lock actuator (driver’s side) are changed, ETACS-ECU activates all the door lock actuators to lock or unlock all the doors.

COMMENTS ON TROUBLE SYMPTOM


If the central door locking system does not work at all, a malfunction of the front door lock actuator (driver’s side) or ETACS-ECU is suspected.

PROBABLE CAUSES



DIAGNOSTIC PROCEDURE


STEP 1. M.U.T.-III diagnosis code


Check that ETACS-ECU sets a diagnosis code.

Q. Is the diagnosis code set?

Refer to GROUP 54A - Troubleshooting .

Go to Step 2.

STEP 2. M.U.T.-III data list


Check the signals related to the central door locking system operation.
Item No.
 Itemname
 Normal condition
271
 Dr door unlock switch
 Not Unlock→ Unlock

<Vehicles with KOS>
Item No.
 Itemname
 Normal condition
272
 As door unlock switch
 Not Unlock→ Unlock
OK: Normal conditions are displayed for all the items.

Q. Is the check result normal?

Go to Step 3.

Refer to GROUP 54A - Inspection procedure 4 "The front door lock actuator (driver’s side) signal is not received ."

STEP 3. Connector check: C-309 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 4.

Repair the defective connector.

STEP 4. Check the wiring harness between C-309 ETACS-ECU connector terminal No. 2 and fusible link (38).



Q. Is the check result normal?

Go to Step 5.

Repair the wiring harness.

STEP 5. Retest the system.


Check that the central door locking system works normally.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace ETACS-ECU.