Inspection Procedure G-5: 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. Alternatively, there are cases where fail-safe function is activated by the following diagnosis codes set in the ETACS-ECU.
Diagnosis code No.
 Fail-safe operation
B1744
 The hazard warning lamps do not flash when the hazard lamp switch is turned on.

PROBABLE CAUSES



DIAGNOSIS 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 G-1 "The turn-signal lamps do not illuminate ."

STEP 2. M.U.T.-III diagnosis code.


Check that ETACS-ECU sets a diagnosis code.

Q. Is the diagnosis code set?

Refer to diagnosis code chart .

Go to Step 3.

STEP 3. Check the power supply circuit.


When the ignition switch is at the "LOCK" (OFF) position, check that the functions below work normally.

Q. Is the check result normal?

Go to Step 4.

Refer to inspection procedure A-1 "Check the ETACS-ECU battery power supply circuit ."

STEP 4. M.U.T.-III data list


Check the input signal from 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?

Go to Step 5.

Refer to inspection procedure J-4 "The hazard warning lamp switch signal is not received ."

STEP 5. 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 use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the ETACS-ECU. Then perform the variant coding and write the VIN data (Refer to GROUP 00, Precautions Before Service - How to Perform Variant Coding ).