Inspection Procedure 1

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.


















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 front 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. Checking keyless entry system operation

Check that the keyless entry system works normally.

Q. Is the check result normal?

YES Go to Step 2.
NO [Vehicles with KOS] : Inspection Procedure 15."
NO [Vehicles with WCM] : Inspection Procedure 5."
STEP 2. Using scan tool MB991958, read the diagnostic trouble code.





(1)
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.

Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(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. Electronic Time and Alarm Control System (ETACS).

NO Go to Step 3.

STEP 3. Using scan tool MB991958, check data list.

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





(1)
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.

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

- Turn the door lock switch of the power window main switch (or front power window sub switch) to the lock direction.





- Turn the door lock switch of the power window main switch (or front power window sub switch) to the unlock direction.





(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 4.

NO Inspection Procedure 4."

STEP 4. Connector check: C-309 ETACS-ECU connector

Q. Is the check result normal?

YES Go to Step 5.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 5. Check the wiring harness between C-309 ETACS-ECU connector terminal No. 2 and fusible link (37).

- Check the power supply line for open and short circuit.

Q. Is the wiring harness between C-309 ETACS-ECU connector terminal No. 2 and fusible link (37) in good condition?

YES : Go to Step 6.
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 6. Check ETACS-ECU connector C-301 and C-315 for loose, corroded, damaged terminals or terminals pushed back in the connector.

Q. Are ETACS-ECU connector C-301 and C-315 in good condition?

YES Go to Step 7.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 7. Central door lock switch check

Check that the central door lock switch is in good condition. Refer to Central Door Lock Switch Check Testing and Inspection.

Q. Is the central door lock switch in good condition?

YES Go to Step 8.
NO Replace the power window main switch.
STEP 8. Check of the wiring harness between E-15 power window main switch connector terminal No. 10 and body ground.

- Check the ground wire for open circuit.

NOTE:
Prior to the wiring harness inspection, check the C-128 intermediate connector and repair if necessary.

Q. Is the wiring harness between E-15 power window main switch connector terminal No. 10 and body ground in good condition?

YES : Go to Step 9.
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 9. Check of the wiring harness between the C-301 ETACS-ECU connector terminal No. 2 and the E-15 power window main switch connector terminal No. 14, the C-315 ETACS-ECU connector terminal No. 15 and the E-15 power window main switch connector terminal No. 13

- Check the power supply line for open or short circuit.

NOTE:
Prior to the wiring harness inspection, check the C-129 intermediate connector and repair if necessary.

Q. Are the wiring harness between the C-301 ETACS-ECU connector terminal No. 2 and the E-15 power window main switch connector terminal No. 14, the C-315 ETACS-ECU connector terminal No. 15 and the E-15 power window main switch connector terminal No. 13 in good condition?

YES : Go to Step 10.
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 10. 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 works normally.