Inspection Procedure E-1

Keyless Entry System: Keyless entry system does not operate.

NOTE: This troubleshooting procedure requires the use of scan tool MB991502 and SWS monitor kit MB991862. For details on how to use the SWS monitor, refer to "How to use SWS monitor".

Transmitter ("LOCK"/"UN LOCK") 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.

Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS Monitor Kit

STEP 1. Use scan tool MB991502 to select "ECU COMM CHK" on the SWS monitor display.
Check the ETACS-ECU.

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 (16-pin).
2. Connect SWS monitor kit MB991862 to the column switch connector (13-pin).
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Operate the scan tool MB991502 according to the procedure below to display "ECU COMM CHECK."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "ECU COMM CHK".
5. Scan tool MB991502 should show "OK" on the "ECU COMM CHK" menu for the "ETACS ECU" menu.

Q: Is "OK" displayed on the "ETACS ECU" menu?

YES: Go to Step 2.

NO: Refer to Inspection Procedure A-3 "Communication with ETACS-ECU is not possible."

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




1. Connect scan tool MB991502 to the data link connector (16-pin).
2. Operate the 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 pushed, does scan tool MB991502 sound?

YES: Replace the ETACS-ECU. Verify that all the doors can be locked or unlocked by using the transmitter.

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