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) Circuit:

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

TROUBLESHOOTING HINTS
- Malfunction of the driver's or front passenger's door lock actuator switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface
- 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 switch.

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 to the data link connector.
2. 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 Checking."

3. Lock or unlock the driver's inside lock knob.
4. Check the 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. Check that all the doors can be locked or 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."