Inspection Procedure 1

Inspection Procedure 1: The Hazard Warning Lights Do Not Illuminate.

CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

TECHNICAL DESCRIPTION (COMMENT)
If the hazard warning light does not illuminate, the hazard warning light switch input circuit in center panel unit or the ETACS-ECU may have a problem.

TROUBLESHOOTING HINTS
- Malfunction of center panel unit
- Malfunction of the ETACS-ECU
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Check that the turn-signal light operate.

Check that the turn-signal lights illuminate normally.

Q : Does turn-signal light work normally?

YES : Go to Step 2.

NO : Diagnose the headlights. Refer to Inspection Procedure 11 "All the turn-signal lights do not illuminate". Inspection Procedure 11

STEP 2. Using scan tool MB991958, check data list.

Using the ETACS-ECU service data, check the hazard warning light signal.

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. Refer to "How to connect scan tool (M.U.T.-III)." Scan Tool Connecting
2.Turn the ignition switch to the "ACC" position.
3.Turn "ON" the hazard light switch.






Q : Does scan tool MB991958 display the items "Hazard switch" as normal condition?

YES : (Normal condition is displayed for item) Go to Step 3.

NO : (Normal condition is not displayed for item No. 265.) Troubleshoot the ETACS-ECU. Refer to ETACS, Diagnosis - Inspection Procedure 10 "ETACS-ECU does not receive any signal from the hazard warning light switch". Inspection Procedure 10

STEP 3. Retest the system

Check that the hazard warning light illuminate normally.

Q : Does the taillight work normally?

YES : The trouble can be an intermittent malfunction (Refer to General (Body and Chassis), How to use Troubleshooting/inspection Service Points, How to Cope with Intermittent Malfunction).

NO : Replace the ETACS-ECU.