Inspection Procedure C-4: The Hazard Warning Lamp Switch Signal is not Received.


caution Whenever the ECU is replaced, ensure that the input signal circuit is normal.


COMMENTS ON TROUBLE SYMPTOM




  • Keyless entry system (encrypted code registration)
  • Hazard warning lamp

PROBABLE CAUSES



  • Malfunction of the hazard warning lamp switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-07 hazard warning lamp switch connector


Q. Is the check result normal?

Go to Step 2.

Repair the defective connector.

STEP 2. Check the hazard warning lamp switch.
Refer to .

Q. Is the check result normal?
Go to Step 3.
Replace the hazard warning lamp switch.

STEP 3. Resistance measurement at the C-07 hazard warning lamp switch connector.


(1)Disconnect the connector, and measure at the wiring harness side.

(2)Resistance between C-07 hazard warning lamp switch connector terminal No.2 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

STEP 4. Check the wiring harness between C-07 hazard warning lamp switch connector terminal No.2 and the body earth.



  • Check the earth wires for open circuit.

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 ).

Repair the wiring harness.

STEP 5. Connector check: C-219 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Check the wiring harness between C-219 ETACS-ECU connector terminal No.71 and C-07 hazard warning lamp switch connector terminal No.1.





  • Check the input line for open circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.

STEP 7. M.U.T.-III data list
Check the input signals from the hazard warning lamp switch.

  • Operate the hazard warning lamp switch.
Item No.
 Item name
 Normal condition
26
 Hazard warning lamp switch
 OFF to ON (only when switch is operated)
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.