42A-CENTRAL DOOR LOCKING SYSTEM DOES NOT OPERATE

INSPECTION PROCEDURE 1: Central door locking system does not work at all.

caution

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

OPERATION

The ETACS-ECU controls the central door locking system, locking or unlocking all the doors by activating the door lock relay or the door unlock relay (built in the ETACS-ECU). The ETACS-ECU uses input signals from the front door lock actuator (driver’s side).

CIRCUIT OPERATION

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.

TROUBLESHOOTING HINTS

Malfunction of the front door lock actuator (driver’s side)
Malfunction of ETACS-ECU
Damaged wiring harness and connectors

DIAGNOSIS

STEP 1. Using scan tool (M.U.T-III), read the diagnostic trouble code.

(1)

caution

To prevent damage to scan tool (M.U.T-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T-III).

Connect scan tool (M.U.T-III). Refer to "How to connect scan tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Check whether the ETACS-ECU related DTC is set.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the DTC set?

Diagnose the ETACS-ECU. Refer to GROUP 54A, Diagnostic trouble code chart

Go to Step 2

STEP 2. Using scan tool (M.U.T-III), check data list.

Check the signals related to the central door locking system operation.

(1)

caution

To prevent damage to scan tool (M.U.T-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T-III).

Connect scan tool (M.U.T-III). Refer to "How to connect scan tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Check the data list of the ETACS.

Inside handle lock knob (driver’s side): Unlock → Lock.

Item No.	Item name	Normal condition
20	Driver's door unlock switch	ON → OFF
21	Driver's door lock switch	OFF → ON

Inside handle lock knob (driver’s side): Lock → Unlock.

Item No.	Item name	Normal condition
20	Driver's door unlock switch	OFF → ON
21	Driver's door lock switch	ON → OFF

OK: Normal condition is displayed.

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. Check of short to power supply, short to ground, and open circuit in D/LOCK line between ETACS-ECU connector and fusible link.

Is the check result normal?

Go to Step 4

Repair the wiring harness.

STEP 4. Retest the system.

Check that the central door locking system works normally.

Is the check result normal?

No action is necessary and testing is complete.

Replace ETACS-ECU.