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.
  • 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 .)

OPERATION


The ETACS-ECU controls the central door locking system, locking or unlocking all the doors by activating the central door lock relay (built in the ETACS-ECU). The ETACS-ECU uses input signals from the door lock switch, which is incorporated in the power window main switch.

COMMENTS ON TROUBLE SYMPTOM


If the central door locking system does not work at all, a malfunction of the door lock switch (built in the power window main switch), 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 - Diagnosis Code Chart .
Go to Step 2.

STEP 2. M.U.T.-III data list
Check the ETACS-ECU service items related to the central door locking system operation.

  • Door lock switch: Unlock → Lock.
Item No.
 Item name
 Normal condition
270
 Dr door lock switch
 Not lock→Lock
271
 Dr door unlock switch
 Unlock→Not unlock

  • Door lock switch: Lock → Unlock.
Item No.
 Item name
 Normal condition
270
 Dr door lock switch
 Lock→Not lock
271
 Dr 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 - Trouble Symptom Chart for Input Signal .

STEP 3. Check of short to power supply, short to earth, and open circuit in +B2 line between ETACS-ECU connector and fusible link.

Q. Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.

STEP 4. Central door lock switch check.
Check that the central door lock switch is in good condition. Refer to Central Door Lock Switch Check .

Q. Is the check result normal?
Go to Step 5.
Replace the power window main switch.

STEP 5. Check of open circuit in earth line between power window main switch connector and body earth.

Q. Is the check result normal?
YES : Go to Step 6.
Repair the connector(s) or wiring harness.

STEP 6. Check of short to power supply, short to earth, and open circuit in D-LS, D-US line between ETACS-ECU connector and power window main switch connector.

Q. Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.

STEP 7. Retest the system.
Check that the central door locking system works normally.

Q. Is the check result normal?
YES : No action is necessary and testing is complete.
Replace ETACS-ECU.