Inspection Procedure C-1

INSPECTION PROCEDURE C-1: Central Door Locking System: The central door locking system does not work at all.

NOTE:
This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor How to Use SWS Monitor."






















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 key cylinder switch
- 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

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
- MB991813: SWS Monitor Kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness

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

Check the ETACS-ECU.









(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 special tool MB991910 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.

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."

.....Select "Interactive Diagnosis."

.....Select "System Select."

.....Select "SWS."

.....Select "SWS MONITOR."

.....Select "ECU COMM Check."
(4)M.U.T.-III should show "OK" on the "ECU COMM Check" menu for the "ETACS ECU" menu.

Q. Is "OK" displayed for the "ETACS ECU" menu?

YES Go to Step 2.

NO Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible Inspection Procedure A-3."

STEP 2. Check ETACS-ECU connector C-217 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is ETACS-ECU connector C-217 in good condition?

YES Go to Step 3.

NO Repair or replace the damaged component(s). Harness Connector Inspection. Verify that the central door locking system works normally.

STEP 3. Check the battery power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-217.





(1)Disconnect ETACS-ECU connector C-217 and measure the voltage available at the junction block side of the connector.





(2)Measure the voltage between terminal 2 and ground.

- The voltage should measure approximately 12 volts (battery positive voltage)

Q. Is the measured voltage approximately 12 volts (battery positive voltage)?

YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Encrypted Code Registration Criteria Table. Verify that all the doors can be locked and unlocked normally.

NO Go to Step 4.

STEP 4. Check the wiring harness between ETACS-ECU connector C-217 (terminal 2) and fusible link (1).

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

















NOTE:
Also check junction block connector C-204 and intermediate connector C-24 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-204 or intermediate connector C-24 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between ETACS-ECU connector C-217 (terminal 2) and fusible link (1) in good condition?

YES No action is necessary and testing is complete.

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.