Inspection Procedure I-9

INSPECTION PROCEDURE I-9: Headlight and Taillight: Headlight automatic shutoff 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 How to Use SWS Monitor."






CIRCUIT OPERATION

The ETACS-ECU operates the headlight automatic shutdown function under the following conditions:

- Ignition key: Other than "ON" position
- Driver's door: open
- Taillights or headlights: ON

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

- 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 front-ECU may be defective
- The ETACS-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
- MB991910: M.U.T.-III Main Harness A
- MB991813: SWS Monitor Kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness

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"









(1)
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 MB991910 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.

Connect the special tool. Refer to "How to connect SWS monitor How to Connect SWS Monitor."
(2)Turn the ignition switch to the "LOCK" (OFF) position.
(3)Operate scan tool MB991958 according to the procedure below to display "H/L AUTO-CUT."

.....Select "Interactive Diagnosis."

.....Select "System select."

.....Select "SWS."

.....Select "SWS MONITOR."

.....Select "Function Diag."

.....Select "LIGHTING."

.....Select "H/L AUTO-CUT."
(4)Check that normal conditions are displayed for the items described in the table below.





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





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

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

Normal condition is not displayed for "TAILLIGHT SW" : Refer to Inspection Procedure M-6 "ETACS-ECU does not receive any signal from the taillight switch Inspection Procedure M-6."

Normal condition is not displayed for "HEADLIGHT SW" : Refer to Inspection Procedure M-6 "ETACS-ECU does not receive any signal from the headlight switch Inspection Procedure M-6."

Normal condition is not displayed for "IG SW (IG1)" : Refer to Inspection Procedure M-2 "ETACS-ECU does not receive any signal from the ignition switch (IG1) Inspection Procedure M-2."

Normal condition is not displayed for "FRONT DOOR SW" : Refer to Inspection Procedure M-5 "ETACS-ECU does not receive any signal from the door switches Inspection Procedure M-5."

Normal condition is not displayed for "H/L AUTO-CUT" : Replace the ETACS-ECU. Check that the headlight automatic shutdown function works normally.