Inspection Procedure 3: Either Automatic Levelling does not Operate.


caution Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.














COMMENTS ON TROUBLE SYMPTOM


If either automatic levelling does not operate, wiring harness and connectors between the headlamp automatic levelling-ECU and the headlamp levelling unit or the headlamp assembly (headlamp levelling unit) may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Headlamp levelling unit check


Perform a levelling motor drive test of the headlamp levelling unit to check that the motor is driven. Refer to .

Q. Is the check result normal?

YES (Intermittent malfunction) : Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .

NO (The left levelling motor is not driven) : Go to Step 2.

NO (The right levelling motor is not driven) : Go to Step 5.

STEP 2. Connector check: D-125 Headlamp automatic levelling-ECU connector and A-21 Headlamp levelling unit (LH) connector


Q. Is the check result normal?

Go to Step 3.

Repair the defective connector.

STEP 3. Check the wiring harness between D-125 headlamp automatic levelling-ECU connector (terminal No. 2, 3, 4) and A-21 headlamp levelling unit (LH) connector (terminal No. 1, 2, 3).


note Prior to the wiring harness inspection, check intermediate connector D-239, and repair if necessary.

Q. Is the check result normal?

Go to Step 4.

Repair the wiring harness.

STEP 4. Retest the system.


Check that the automatic levelling of the left headlamp operates normally.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

Replace the headlamp assembly (LH).

STEP 5. Connector check: D-125 Headlamp automatic levelling-ECU connector and A-42 Headlamp levelling unit (RH) connector


Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Check the wiring harness between D-125 headlamp automatic levelling-ECU connector (terminal No. 11, 12, 13) and A-42 headlamp levelling unit (RH) connector (terminal No. 1, 2, 3).



note Prior to the wiring harness inspection, check intermediate connector D-239, and repair if necessary.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.

STEP 7. Retest the system.


Check that the automatic levelling of the right headlamp operates normally.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

Replace the headlamp assembly (RH).