Inspection Procedure J-8

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

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."

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
- Taillight switch
- Headlight switch

TECHNICAL DESCRIPTION (COMMENT)
If the function does network normally, the input circuit system from the switches, the ETACS-ECU or the front-ECU may be defective (refer to "CIRCUIT OPERATION").

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
- The front-ECU may be defective

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-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 with the scan tool?

YES: Go to Step 2.

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

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. Connect special tool MB991911 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.




1. Connect the special tool. Refer to "How to connect SWS monitor."
2. Operate scan tool MB991958 according to the procedure below to display "H/L AUTO-CUT."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "LIGHTING."
g. Select "H/L AUTO-CUT"




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




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

Q: Does the scan tool MB991958 display the items "TAILLIGHT SW", "IG SW (IG1)", "FRONT DOOR SW" and "H/L AUTO-CUT" as normal condition?

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

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

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

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

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