Inspection Procedure M-1
Interior Light: The front dome light and rear dome light do not illuminate or go out normally.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."
Interior Light Automatic Shutt-down Function Circuit:
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
Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS monitor kit
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 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 data link 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 3.
NO: Refer to Inspection Procedure A-3 "Communication with 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 following switches:
- Ignition switch: ON or START
- Driver's door: open
Operate the scan tool MB991502 according to the procedure below to display "ETACS ECU."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "DATA LIST"
5. Select "ETACS ECU"
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:
- Normal condition is not displayed on the "IG SW (IG1)": Refer to Inspection Procedure N-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."
- Normal condition is not displayed on the "FRONT DOOR SW': Refer to Inspection Procedure N-5 "ETACS-ECU does not receive a signal from the driver's or the front passenger's door switch."
STEP 4. Check the input signal by using the pulse check mode of the monitor.
Check the following switches and input signals:
- Key reminder switch
- All door switches
- Interior light loaded signal
Operate the scan tool MB991502 according to the procedure below to display "PULSE CHECK."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "PULSE CHECK."
Check if scan tool MB991502 sounds or not.
Q: When the key reminder switch, each door switch and the interior light are operated, does scan tool MB991502 sound in each case?
YES: Replace the ETACS-ECU. Verify that the dome light illuminates normally.
NO:
- Scan tool MB991502 does not sound when the ignition key is removed and reinserted.: Refer to Inspection Procedure O-1 "ETACS-ECU does not receive a signal from the key reminder switch."
- When one of the doors is opened and closed, scan tool MB991502 does not sound: Refer to Inspection Procedure O-4 "ETACS-ECU does not receive a signal from all the door switches."
- When one of the interior lights is illuminated, scan tool MB991502 does not sound: Refer to Inspection Procedure O-10 "ETACS-ECU does not receive any multi-purpose fuse No. 17 loaded signal."