Inspection Procedure E-1

Keyless Entry System: Keyless entry system does not operate.

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

NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor". How To Use SWS Monitor

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
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- MB991813: SWS Monitor Kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness
- MB991854: SWS Monitor Harness (For 13-pin)

STEP 1. Use scan tool MB991958 to select "ECU COMM CHK" on the SWS monitor display.
Check the ETACS-ECU.

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 (16-pin).
2. Connect SWS monitor harness MB991854 to the data link connector (13-pin).
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Operate the scan tool MB991958 according to the procedure below to display "ECU COMM CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "ECU COMM CHK".

5. Scan tool MB991958 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 the ETACS-ECU is not possible."

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




1. Connect scan tool MB991958 to the data link connector (16-pin).
2. Operate the scan tool MB991958 as follows:
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "PULSE CHECK."

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

Q: When the transmitter "LOCK" or "UNLOCK" switch is pushed, does scan tool MB991958 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 0-9 "The ETACS-ECU does not receive a signal from the lock or unlock switch".