Inspection Procedure C-5

Central Door Locking System: All the Doors do not Lock with just the Driver's or Front Passenger's Inside Lock Knob Operation.

Central Door Lock (Door Lock Actuator Switch) Circuit:

TECHNICAL DESCRIPTION
The driver's or front passenger's door lock actuator switch or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- The driver's and passenger's door lock actuator switch may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface (V.C.I.)
- MB991827: MUT-III USB cable
- MB991911: MUT-III Main harness B

Check the input signal (by using the Pulse check mode of the monitor).
Check the input signals from the driver's or front passenger's door lock actuator.

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 the special tool. Refer to "How to connect SWS monitor." How to Connect SWS Monitor
2. When the driver's inside lock knob is locked or unlocked, check if scan tool MB991958 sounds or not.
3. Operate scan tool MB991958 according to the procedure below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "PULSE CHECK."

4. Check scan tool MB991958 sounds or not.

Q: Does scan tool MB991958 sound when the driver's or the front passenger's inside lock knob is moved from "LOCK" to "UNLOCK" or vice versa?

YES: Replace the ETACS-ECU. All the doors should be locked and unlocked by operating the driver's inside lock knob.

NO: Refer to Inspection Procedure P-5 "ETACS-ECU does not receive a signal from the driver's or front passenger's door lock actuator switch."