Inspection Procedure M-4

Interior Light: The interior light automatic shut-down function does not work normally.

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)
- Door switch (front: LH)
- All door switches
- 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
- The door switch 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
- MB991911: MUT-III Main Harness B
- MB991862: SWS Monitor Kit

STEP 1. Verify 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?

The front dome light and the rear dome light do illuminate normally : Go to Step 2.

Neither the front dome light nor the rear dome light illuminates normally : Refer to Inspection Procedure M-1 "The front dome light, rear dome light and luggage compartment 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 "The front dome light, rear dome light or luggage compartment light does not illuminate or go out normally."

STEP 2. 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. Connect the DLC harness before connecting the column-ECU harness. Be sure to connect SWS monitor kit MB991862 after turning on scan tool MB991958.

1. Connect scan tool MB991958 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 scan tool MB991958 according to the procedure below to display "ECU COMM CHK."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. 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 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: OFF
- Driver's and front passenger's door: open

Operate scan tool MB991958 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?

Normal conditions are displayed for all the items : Go to Step 4.

Normal condition is not displayed for "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 for "IG SW (ACC)" : Refer to Inspection Procedure N-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 N-4 "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:
- Interior light loaded signal

Operate scan tool MB991958 according to the procedure below to display "PULSE CHECK."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "PULSE CHECK."

Check if scan tool MB991958 sounds or not.

Q: Does scan tool MB991958 sound when the interior light loaded signal is operated?

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

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