Inspection Procedure M-1
Interior Light: The front dome light, rear dome lightNOTE: This troubleshooting procedure requires the use of scan tool MB991502 or MB991958 and SWS monitor kit MB991813. For details on 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 illuminates the front dome light.. the rear dome light and the luggage compartment 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, the rear dome light and luggage compartment 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
- Trouble in input signal system
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The ETACS-ECU may be defective
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991496: Main unit
- MB991497: Test Harness (for communication)
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness
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 or MB991958 to select "ECU COMM Check" on the SWS monitor display.
Check the ETACS-ECU
CAUTION: To prevent damage to scan tool MB991502 or MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502 or MB991958. Connect special tool MB991497 or MB991911 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991496 or MB991824.
1. Connect the special tool. Refer to "How to connect SWS monitor."
2. Turn the ignition switch to the "LOCK" (OFF) position.
3. Operate scan tool MB991502 or MB991958 according to the procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."
4. Scan tool MB991502 or MB991958 should show "OK" on the "ECU COMM Check" 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
1. Operate scan tool MB991502 or MB991958 according to the procedure below to display "ETACS ECU."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. 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"?
Normal conditions are displayed for all the items: Go to Step 4.
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 "Function Diag." menu of the SWS monitor.
Check the input signals from the following switches:
- Key reminder switch
- All door switches
- Interior light loaded signal
1. Operate scan tool MB991502 or MB991958 according to the procedure below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."
2. Check scan tool MB991502 or MB991958 sounds.
Q: When the key reminder switch, each door switch and the interior light are operated, does scan tool MB991502 or MB991958 sound in each case?
Buzzer of scan tool MB991502 or MB991958 sounds normally: Replace the ETACS-ECU. Verify that the dome light illuminates normally.
Scan tool MB991502 or MB991958 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 or MB991958 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 or MB991958 does not sound: Refer to Inspection Procedure O-10 "ETACS-ECU does not receive any interior light loaded signal."