Inspection Procedure 10: The hazard warning lamp switch signal is not received.


caution
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)

COMMENTS ON TROUBLE SYMPTOM


The hazard warning lamp switch input signal is used for the operation judgement of hazard warning lamp. Therefore, if the signal is abnormal, the hazard warning lamp will not illuminate.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Check the hazard indicator assembly.


Refer to .

Q. Is the check result normal?

Go to Step 2.

Replace the hazard indicator assembly.

STEP 2. Resistance measurement at hazard indicator assembly connector (earth terminal)


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the hazard indicator assembly connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 4.

Go to Step 3.

STEP 3. Check of open circuit in earth line between hazard indicator assembly connector and body earth


Q. Is the check result normal?

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the connector(s) or wiring harness.

STEP 4. Check of short to power supply, short to earth, and open circuit in HAZ line between ETACS-ECU connector and hazard indicator assembly connector


Q. Is the check result normal?

Go to Step 5.

Repair the connector(s) or wiring harness.

STEP 5. M.U.T.-III data list


Check the input signals from the hazard warning lamp switch.

Item No.
 Item name
 Normal condition
Item 265
 Hazard switch
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the ETACS-ECU.