Inspection Procedure C-4

INSPECTION PROCEDURE C-4: Central Door Locking System: None of the doors lock and unlock with just the driver's or passenger's inside lock knob operation.






TECHNICAL DESCRIPTION

The door lock actuator or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS

- Trouble in input signal system
- 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

Check the input signal (by using the pulse check mode of the monitor).

Check the input signals from the driver's or passenger's door lock actuator.





(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 the special tool. Refer to "How to connect SWS monitor How to Connect SWS Monitor."
(2)Operate scan tool MB991958 according to the procedure below to display "Pulse check."

.....Select "Interactive Diagnosis."

.....Select "System Select."

.....Select "SWS."

.....Select "Pulse Checking."
(3)When the driver's inside lock knob is locked or unlocked, check if scan tool MB991958 sounds or not.

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

YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Encrypted Code Registration Criteria Table.
Check that all the doors can be locked or unlocked by operating the driver's inside lock knob.

NO Refer to Inspection Procedure N-3 "ETACS-ECU does not receive any signal from the door lock actuator Inspection Procedure N-3."