Inspection Procedure F-3: The high-beam headlamps do not illuminate normally.



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




COMMENTS ON TROUBLE SYMPTOM


If the high-beam headlamps do not illuminate, the headlamp switch input circuit, the headlamp relay (HI) or the ETACS-ECU may be defective.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. 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 2.

STEP 2. M.U.T.-III data list


Check the input signal from the dimmer switch.

  • Operate the dimmer switch.
Item No.
Item name
Normal condition
05
High beam lamp
ON
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 3.
Refer to Inspection Procedure J-1 "The column switch (lighting and wiper switch) signal is not received ."

STEP 3. M.U.T.-III actuator test


Perform the actuator test for the ETACS-ECU, and check that the tail lamps illuminate normally.

  • Item 05: Head lamp high: OFF
  • Item 06: Head lamp high: ON

Q. Is the check result normal?

Go to Step 9.
Go to Step 4.

STEP 4. Connector check: B-222 headlamp relay (HI) connector




Q. Is the check result normal?

Go to Step 5.

Repair the defective connector.

STEP 5. Check the headlamp relay (HI).


Refer to GROUP 54A - Headlamp .

Q. Is the check result normal?

Go to Step 6.
Replace the headlamp relay (HI).

STEP 6. Voltage measurement at B-222 headlamp relay (HI) connector.




(1)Remove the headlamp relay (HI), and measure at the junction block side.

(2)Voltage between B-222 headlamp relay (HI) connector terminal Nos.1, 3 and body earth
OK: System voltage

Q. Is the check result normal?

Go to Step 8.

Go to Step 7.

STEP 7. Check the wiring harness between B-222 headlamp relay (HI) connector terminal Nos.1, 3 and the fusible link (1).





note Prior to the wiring harness inspection, check the junction block connector B-208, and repair if necessary.

  • Check the power supply line from the fusible link (1) 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 8. Connector check: B-234 ETACS-ECU connector




Q. Is the check result normal?

Go to Step 9.

Repair the defective connector.

STEP 9. Retest the system.


Check that the low-beam headlamps illuminate normally.

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 ).