Inspection Procedure K-2

Flasher Timer: Hazard warning lights do not flash when the hazard warning light switch is turned on.

Hazard Warning Light Circuit:

CIRCUIT OPERATION
If the ETACS-ECU receives "ON" signal from the hazard warning light switch, the ETACS-ECU turns on the flasher timer (incorporated in the ETACS-ECU), thus causing the turn-signal lights to flash

TECHNICAL DESCRIPTION (COMMENT)
If the hazard warning lights do not flash, the power supply line to the ETACS-ECU (dedicated to the turn-signal lights) or the ETACS-ECU may be defective

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:
- 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

STEP 1. Verify the turn-signal lights.

Q: Do the turn-signal lights illuminate normally?

YES: Go to Step 2.

NO: Refer to Inspection Procedure K-1 "Turn-signal lights do not flash when the turn-signal light switch is turned on."

STEP 2. Check the input signal (by using the Pulse check mode of the monitor).
Check input signal from the hazard warning light switch.

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 "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."

3. Check that scan tool MB991958 sounds when the hazard warning light switch is turned from "OFF" to "ON."

Q: Does scan tool MB991958 sound when the hazard warning light switch is turned from "OFF" to "ON"?

YES: Replace the ETACS-ECU. Verify that the hazard warning lights illuminate normally.

NO: Refer to Inspection Procedure O-2 "The ETACS-ECU does not receive any signal from the hazard warning light switch."