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


Input signal from the hazard warning lamp switch is used to operate the functions below. If the signal is abnormal, these functions will not work normally.

PROBABLE CAUSES



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.