Inspection Procedure C-1

Central Door Locking System: The Central Door Lock System does not Work at all.

NOTE: This troubleshooting requires use of scan tool MB991958 and SWS monitor kit MB991862. For details of how to use the SWS monitor, refer to "How to use SWS monitor." How To Use SWS Monitor

Central Door Lock Power Supply Circuit Part 1:

Central Door Lock Power Supply Circuit Part 2:

CIRCUIT OPERATION
- The ETACS-ECU operates the central door lock system according to the following signals:
- Driver's or passenger's door lock actuator switch
- Driver's or passenger's door lock key cylinder switch
- Door lock switch, which is incorporated in the power window main switch or power window sub switch (front RH)

- The ETACS-ECU locks or unlocks all the doors by operating the central door lock relay (incorporated in the ECU) in response to input signals.

TROUBLESHOOTING HINTS
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface
- MB991827: MUT-III USB cable
- MB991911: MUT-III Main harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness

STEP 1. Use scan tool MB991958 to select "ECU COMM Check" on the SWS monitor display.
Check the following ETACS-ECU.

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 special tool MB991911 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.







1. Connect the special tool. Refer to "How to connect SWS monitor." How to Connect SWS Monitor
2. Turn the ignition switch to the "LOCK" (OFF) position.
3. Operate scan tool MB991958 according to the procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."

4. Scan tool MB991958 should show "OK" on the "ECU COMM Check" menus for both the "ETACS ECU" menus.

Q: Is "OK" displayed on the "ETACS ECU" menu?

YES: Go to Step 2.

NO: Refer to Inspection Procedure A-3 "Communication with ETACS-ECU is impossible."

STEP 2. Measure at ETACS-ECU connector C-119 in order to check the fusible link (1) line of power supply system to ETACS-ECU.




1. Disconnect ETACS-ECU connector C-119, and measure at the junction block side.




2. Measure the voltage between terminal 2 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES: Go to Step 5.

NO: Go to Step 3.




STEP 3. Check ETACS-ECU connector C-119 for damage.

Q: Is ETACS-ECU connector C-119 in good condition?

YES: Go to Step 4.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the central door locking system works normally.













STEP 4. Check the wiring harness between ETACS-ECU connector C-119 (terminal 2) and fusible link (1).

NOTE: Also check junction block connector C-113 and intermediate connector C-89. If junction block connector C-113 or intermediate connectors C-89 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between ETACS-ECU connector C-119 (terminal 2) and fusible link (1) in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. Check that the central door locking system works normally.










STEP 5. Check ETACS-ECU connectors C-117, C-119 and driver's door lock actuator connector E-13 for damage.

Q: Are ETACS-ECU connectors C-117, C-119 and driver's door lock actuator connector E-13 in good condition?

YES: Go to Step 6.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the central door locking system works normally.
















STEP 6. Check the wiring harness from ETACS-ECU connectors C-117 (terminal 22) and C-119 (terminal 12) to driver's door lock actuator connector E-13 (terminals 4 and 6).

NOTE: Also check intermediate connector C-91 and junction block connector C-108. If intermediate connector C-91 or junction block connector C-108 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness from ETACS-ECU connectors C-117 (terminal 22) and C-119 (terminal 12) to driver's door lock actuator connector E-13 (terminals 4 and 6) in good condition?

YES: Replace the ETACS-ECU. Check that the central door locking system works normally.

NO: Repair the wiring harness. Check that the central door locking system works normally.