Inspection Procedure J-8

Headlight, Taillight: Headlight automatic shutdown function does not work normally.

Headlight Automatic Shutt-down Function:

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 headlight automatic shutdown function according to the following signals:
- Ignition switch (IG1)
- Driver's door switch
- Tail light switch
- Headlight switch

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

TROUBLESHOOTING HINTS
- The driver's door switch may be defective
- The column switch (lighting and turn-signal switch) may be defective
- The ETACS-ECU may be defective
- The front-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 configuration function operation.

Q: Has the headlight automatic shutdown function been enabled by means of the adjustment function?

YES: Go to Step 2.

NO: Enable the headlight automatic shutdown function been by means of the adjustment function.

STEP 2. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.

Check the input signals from the switches in the following conditions:
- Turn the ignition switch from ON to OFF.
- Turn the lighting switch to the "TAIL" or "HEAD" position.

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. Operate the scan tool MB991958 according to the procedure below to display "H/L AUTO-CUT."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "FUNCTION DIAG."
e. Select "LIGHTING."
f. Select "H/L AUTO-CUT."




4. Check that normal conditions are displayed on the items described in the table.




5. When the driver's door is opened, check that normal conditions are displayed on the items described in the table.

Q: Are normal conditions displayed on the "TAILLIGHT SW", "IG SW (IG1)", "FRONT DOOR SW" and "H/L AUTO-CUT"?

YES : Replace the front-ECU. Verify that the headlight automatic shutdown function now works normally.

NO : Refer to Inspection Procedure N-6 "ETACS-ECU does not receive a signal from the taillight switch."

NO : Refer to Inspection Procedure N-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."

NO : Refer to Inspection Procedure N-5 "ETACS-ECU does not receive a signal from the front door switches."

NO : Replace the front-ECU. Verify that the headlight automatic shutdown function now works normally.