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
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-III Main Harness B

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 "The 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 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. Refer to "How to connect SWS monitor"
2. Operate scan tool MB991958 as follows:
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."

3. Push the transmitter "LOCK" or "UNLOCK" button.
4. Check that scan tool MB991958 sounds.

Q: When the transmitter "LOCK" or "UNLOCK" button is turned ON, does scan tool MB991958 sound?

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

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