Inspection Procedure 3: Either Automatic Levelling does not Operate.

caution

Before replacing the ECU, 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, the wiring harness and connector(s) between the headlamp automatic levelling ECU and the headlamp levelling unit, or the headlamp assembly (headlamp levelling unit) may have a problem.

PROBABLE CAUSES

Malfunction of headlamp assembly (headlamp levelling unit)
Damaged harness wires and connectors

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?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction

).

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: C-112 Headlamp automatic levelling ECU connector, A-37 Headlamp levelling unit (LH) connector

Q. Is the check result normal?

Go to Step 3.

Repair the defective connector.

STEP 3. Wiring harness check between the C-112 headlamp automatic levelling ECU connector terminal No. 2/3/4 and the A-37 headlamp levelling unit (LH) connector terminal No. 10/11/12

Check the power supply lines, earth lines and communication lines for open circuit.

Q. Is the check result normal?

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?

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 headlamp assembly (LH).

STEP 5. Connector check: C-112 Headlamp automatic levelling ECU connector, A-54 Headlamp levelling unit (RH) connector

Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Wiring harness check between the C-112 headlamp automatic levelling ECU connector terminal No. 11/12/13 and the A-54 headlamp levelling unit (RH) connector terminal No. 10/11/12

Check the power supply lines, earth lines and communication lines for open circuit.

Q. Is the check result normal?

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?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction

Headlamp assembly (RH)