Inspection Procedure E-1

Keyless Entry System: Keyless entry system does not operate.

Transmitter ("LOCK"/"UNLOCK") Input Signal:

CIRCUIT OPERATION
A receiver is incorporated in the ETACS-ECU. This receiver receives a lock or unlock signal from the transmitter.

TROUBLESHOOTING HINTS
- The transmitter may be defective
- The ETACS-ECU may be defective

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)

STEP 1. Verify the central door locking system.

Q: Does the central door locking system work normally?

YES: Go to Step 2.

NO: Refer to Inspection Procedure C-1 "Central door locking system does not work at all."

STEP 2. Check the input signal by using the pulse check mode of the monitor.

Check input signals from the transmitter.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.




1. Connect scan tool MB991502 to the data link connector.
2. Operate scan tool MB991502 as follows:
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "PULSE CHECK."

3. Push the transmitter "LOCK" or "UNLOCK" switch.
4. Check that scan tool MB991502 sounds

Q: When the transmitter "LOCK" or "UNLOCK" switch is turned ON, does scan tool MB991502 sound?

YES: Replace the ETACS-ECU. All the doors can be locked or unlocked by means of the transmitter.

NO: Refer to Inspection Procedure N-9 "ETACS-ECU does not receive a signal from the lock or unlock switch."