Inspection Procedure L-2: The hazard warning lamps do not illuminate.


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.


COMMENTS ON TROUBLE SYMPTOM
If the hazard warning lamps do not illuminate, the hazard warning lamp input signal circuit or the ETACS-ECU may be defective.

POSSIBLE CAUSES

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

DIAGNOSTIC PROCEDURE

Step 1. Check that the turn-signal lamps operate.
Check that the turn-signal lamps illuminate normally.

Q. Is the check result normal?
Go to Step 2.
Refer to Inspection Procedure L-1 "The turn signal lamps do not illuminate ."

Step 2. Check the power supply circuit.
When the ignition switch is at the LOCK (OFF) position, check that the functions below work normally.

  • Lamp reminder function
  • Central door locking system
  • Room lamp (excluding interior lamp automatic-shutdown function)

Q. Is the check result normal?
Go to Step 3.
Refer to Inspection Procedure A-2 "When the ignition switch is at the LOCK (OFF) position, the functions do not work normally. Check the battery power supply circuit to the ETACS-ECU ."

Step 3. Pulse check
Check the input signal from the hazard warning lamp switch.
System switch
 Check condition
Hazard warning lamp switch
 When the hazard warning lamp switch is turned from off to on
OK: The M.U.T.-III sounds or the voltmeter needle fluctuates.

Q. Is the check result normal?
Go to Step 4.
Refer to Inspection Procedure P-11 "The hazard warning lamp switch signal is not received ."

Step 4. Retest the system.
Check that the hazard warning lamps illuminate.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.