Inspection Procedure M-1

Interior Light: The front dome light and rear dome light do not illuminate or go out normally.

Interior Light Automatic Shut-down Function Circuit:

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
The ETACS-ECU illuminates the front dome light and the rear dome light according to the following signals:
- ignition switch (IG1)
- key reminder switch
- front door switch (LH)
- all door switches
- driver's door lock actuator switch

TECHNICAL DESCRIPTION (COMMENT)
If the front dome light and the rear dome light do not illuminate normally, the dome light bulb(s) may be burned out or the input circuit system from the switches, the power supply lines to the switches or the ETACS-ECU may be defective (refer to "CIRCUIT OPERATION"). Alternatively, the delay-off function may be set to "0 second" by using the configuration function.

TROUBLESHOOTING HINTS
- The key reminder switch may be defective
- The door switch may be defective
- The driver's door lock actuator switch may be defective
- The dome light may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

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. Verify the adjustment function.

Q: Is the dome light delay-off time set to "7.5 seconds", "10 seconds, "15 seconds" or "30 seconds by using the adjustment function?"

YES: Go to Step 2.

NO: Set the dome light delay-off time to "7.5 seconds", "10 seconds, "15 seconds" or "30 seconds by using the adjustment function." Verify that the dome light illuminates normally.

STEP 2. Use scan tool to select "ECU COMM CHECK" 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 3.

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

STEP 3. Check the input signal by using "DATA LIST" menu of the SWS monitor.

Check the input signals from the switches in the following conditions:
- Turn the ignition switch to the "ON" or "START" position.
- Open the driver's door. (The front door switch (LH) is turned to the ON position.)




1. Operate the scan tool MB991958 according to the procedure below to display "ETACS ECU."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "DATA LIST"
e. Select "ETACS ECU"




2. Check that normal conditions are displayed on the items described in the table.

Q: Are normal conditions displayed on the "IG SW (IG1)" and "FRONT DOOR SW"?

YES : Go to Step 4.

NO : Refer to Inspection Procedure N-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."

NO : Refer to Inspection Procedure N-5 "ETACS-ECU does not receive a signal from the front door switches."

STEP 4. Check the input signal (by using the pulse checking mode of the monitor).

Check the following switches and input signals:
- Key reminder switch
- All door switches
- Interior light loaded signal




1. Operate the scan tool MB991958 according to the procedure below to display "PULSE CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "PULSE CHECK."




2. Check if scan tool MB991958 sounds or not.

Q: When the key reminder switch, each door switch and the interior light are operated, does scan tool MB991958 sound in each case?

YES : Replace the ETACS-ECU. Verify that the dome light illuminates normally.

NO : Refer to Inspection Procedure O-1 "ETACS-ECU does not receive a signal from the key reminder switch."

NO : Refer to Inspection Procedure O-4 "ETACS-ECU does not receive a signal from all the door switches."

NO : Refer to Inspection Procedure O-10 "ETACS-ECU does not receive a interior light loaded signal."