Inspection Procedure 1

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

Central Door Locking System Power Supply Circuit:

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

CIRCUIT OPERATION

- The ETACS-ECU controls the central door lock system, locking or unlocking all the doors by activating the central door lock relay (built into the ETACS-ECU). The ETACS-ECU uses inputs from the following components:
- Door lock actuator
- Door lock switch, which is incorporated in the power window main switch or power window sub switch

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The ETACS-ECU may be defective

DIAGNOSTIC PROCEDURE

Required Special Tools:
- MB992006: Extra fine probe
- MB991223: Harness set
- MB991958: Scan Tool (M.U.T-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T-III USB Cable
- MB991910: M.U.T-III Main Harness A

STEP 1.Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.






1. Connect scan tool MB991958. 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.

Q: Is the DTC set?

YES : Diagnose the ETACS-ECU. Refer to Chassis Electrical, Diagnosis code chart.

NO : Go to Step 2.

STEP 2.Using scan tool MB991958, check data list.

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






CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)."
2. Turn the ignition switch to the "ON" position.
3. Check the data list of the ETACS.

- Set the driver's door to "UNLOCK."






- Set the passenger's door to "UNLOCK." (Vehicles with KOS)






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

OK: Normal conditions are displayed for all items.

Q: Are the check result normal?

YES : Go to Step 3.

NO : Refer to Chassis Electrical - Inspection procedure 4 "The front door lock actuator (driver's side) signal is not received."

STEP 3.Check ETACS-ECU connector C-309 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-309 in good condition?

YES : Go to Step 4.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Verify that the central door locking system works normally.

STEP 4.Check the wiring harness between ETACS-ECU connector C-309 (terminal 2) and fusible link (37).

Q: Is the wiring harness between ETACS-ECU connector C-309 (terminal 2) and fusible link (37) in good condition?

YES : Go to Step 5.

NO : The wiring harness may be damaged or the connector may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the central door locking system works normally.

STEP 5.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.

NO : Replace the ETACS-ECU. Check that the central door locking system normally.