Inspection Procedure 4: The front door lock actuator (driver’s side) signal is not received.

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 .)

COMMENTS ON TROUBLE SYMPTOM

The front door lock actuator (driver’s side) input signal is used for the operation judgement of the functions below. If the signal is abnormal, these functions will not work normally.

Key reminder function
Central door locking
KOS
Keyless entry system
Room lamp

PROBABLE CAUSES

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

DIAGNOSIS PROCEDURE

STEP 1. Front door lock actuator (driver’s side) check

Refer to GROUP 42A - Door

Q. Is the check result normal?

Go to Step 2.

Replace the front door lock actuator (driver’s side).

STEP 2. Resistance measurement at front door lock actuator (LH) connector (earth terminal)

(1)Disconnect the connector, and measure at the wiring harness side.

(2)Measure the resistance between the door lock actuator (LH) connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 4.

Go to Step 3.

STEP 3. Check of open circuit in earth line between front door lock actuator (LH) connector and body earth

Q. Is the check result normal?

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

Repair the connector(s) or wiring harness.

STEP 4. Check of short to power supply, short to earth, and open circuit in DDUK line between ETACS-ECU connector and front door lock actuator (LH) connector

Q. Is the check result normal?

Go to Step 5.

Repair the connector(s) or wiring harness.

STEP 5. M.U.T.-III data list

Change the status of driver’s door from unlocked to locked.

Item No.	Item name	Normal condition
Item 271	Dr door unlock switch	Unlock → Lock

OK: Normal condition is displayed.

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.