Inspection Procedure J-9

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

Headlight Automatic Shut-down Function:

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 (turn-signal light and lighting 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
- MB991911: MUT-III 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 configuration function.

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 following switches:
- Ignition switch: "ON" to "OFF"
- Lighting switch: "TAIL" or "HEAD"

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. Also 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. Operate scan tool MB991958 according to the procedure below to display "H/L AUTO-CUT."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "FUNCTION DIAG."
5. Select "LIGHTING."
6. 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"?

Normal conditions are displayed for all the items : Replace the front-ECU. Verify that the headlight automatic shutdown function now works normally.

The scan tool does not show the respective normal condition for item "TAILLIGHT SW" : Refer to Inspection Procedure N-5 "ETACS-ECU does not receive a signal from the taillight switch."

The scan tool does not show the respective normal condition for item "IG SW (IG1)" : Refer to Inspection Procedure N-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."

The scan tool does not show the respective normal condition for item "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."

The scan tool does not show the respective normal condition for item "H/L AUTO-CUT" : Replace the front-ECU. Verify that the headlight automatic shutdown function now works normally.