Inspection Procedure M-4

Interior Light: The Interior Light Automatic Shut Down Function Does Not Operate Correctly.

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

Interior Light Automatic Shut-down Function Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the interior light automatic shutdown function according to the following switch signals:
- Ignition switch (ACC)
- Ignition switch (IG1)
- Front door switch
- interior light loaded signal

TECHNICAL DESCRIPTION (COMMENT)
If the function does not work normally, the input circuit system from the switches or the ETACS-ECU may be defective (refer to "CIRCUIT OPERATION").

TROUBLESHOOTING HINTS
- Malfunction of the door switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

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

STEP 1. Check the front dome light and the rear dome light.
If the front dome light switch and the rear dome light switch are moved to the "door interlock position", the front dome light and the rear dome light should illuminate when either door is opened.

Q: Do the front dome light and the rear dome light illuminate normally?

YES: Go to Step 2.

NO:
- Neither the front dome light nor the rear dome light illuminates normally: Refer to Inspection Procedure M-1 "Dome light, luggage compartment light and trunk light do not illuminate or go out normally."
- Either the front dome light or the rear dome light illuminates normally: Refer to Inspection Procedure M-2 "Dome light, luggage compartment light and trunk light do not illuminates or goes out 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 MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502. Also connect SWS monitor kit MB991862 after turning on scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Connect SWS monitor kit MB991862 to the column switch connector.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Operate the MUT-II 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 CHECK."
5. Scan tool MB991502 should show "OK" on 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 impossible."

STEP 3. Check the input signal by using "DATA LIST" of the SWS monitor.
Check the input signals from the following switches:
- Ignition switch: OFF
- Driver's or front passenger's door: open Operate the MUT-II 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: Does the scan tool display the items "IG SW (IG1)", "IG SW (ACC)" and "FRONT DOOR SW" as normal condition?

YES: Go to Step 4.

NO:
- Normal condition is not displayed for "IG SW (IG1)": Refer to Inspection procedure O-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."
- Normal condition is not displayed for "IG SW (ACC)": Refer to Inspection procedure O-1 "ETACS-ECU does not receive a signal from the ignition switch (ACC)."
- Normal condition is not displayed for "FRONT DOOR SW": Refer to Inspection procedure O-6 "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).
Check the following switches and input signals:
- Interior light loaded signal

Operate the MUT-II 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: Does scan tool MB991502 sound when the interior light loaded signal is operated?

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

NO: Refer to Inspection Procedure P-14 "ETACS-ECU does not receive a interior light loaded signal."