Inspection Procedure M-4
Interior light: The interior light automatic shut-down function does not operate correctly.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 operates the interior light automatic shutdown function according to the following switch signals:
- Ignition switch (ACC)
- Ignition switch (IG1)
- Front door switch (LH)
- All door switches
- Multi-purpose fuse No.17-loaded signal
TECHNICAL DESCRIPTION (COMMENT)
If the function does network 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
- 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 front dome light and the rear dome light operation.
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
NO
NO
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.
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 "OFF" position.
- Open the driver's door or front passenger's door.
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 below.
Q: Does the scan tool display the items "IG SW (IG1)", "IG SW (ACC)" and "FRONT DOOR SW" as normal condition?
YES
NO
NO
NO
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
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: 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."