Headlight automatic leveling warning light always on (Headlight Automatic Leveling Control)

1. Headlight auto leveling system check

Refer to "65.Lighting Control 10J.Troubleshooting(Headlight Automatic Leveling Control) diagnostic system check-headlight auto leveling controls".

2. Current DTC check

1) Turn OFF the ignition switch.

2) Connect the scan tool.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

Go to the applicable DTC diagnosis.

No

=>Go to Learned value reset in headlight auto leveling control unit.

3. Learned value reset in headlight auto leveling control unit

1) Turn ON the ignition switch.

2) Short-circuit the No. 4 and No. 12 pins of the DLC.

3) Turn the headlight switch from OFF to ON within 20 seconds.

4) After 3 seconds or more have passed, depress the brake pedal 3 times.

5) Check the headlight automatic leveling warning light. Does the headlight automatic leveling warning light turn OFF?

Yes

=>Go to Repair verification.

No

=>Go to Headlight automatic leveling warning light operation check.

4. Headlight automatic leveling warning light operation check

1) Turn ON the ignition switch.

2) Check the headlight automatic leveling warning light. Does the headlight automatic leveling warning light illuminate for 3 seconds and then turn OFF?

Yes

Go to Intermittent conditions of lighting control system.

Refer to "224.Lighting Control 37D.Symptom(Headlight Automatic Leveling Control) intermittent conditions of lighting control system".

No

=>Go to Headlight automatic leveling warning light illumination check.

5. Headlight automatic leveling warning light illumination check

1) Turn OFF the ignition switch.

2) Disconnect the headlight auto leveling control unit harness connector (C99).

Refer to "LHD Headlight Leveling (Auto Leveling)" in the ETM (wiring diagram). (Open using the ETM viewer.).

3) Turn ON the ignition switch.

4) Check the headlight automatic leveling warning light. Does the headlight automatic leveling warning light flash?

Yes

=>Go to Headlight auto leveling control unit replacement.

No

=>Go to Instrument panel cluster replacement.

6. Headlight auto leveling control unit replacement

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control headlight auto leveling control unit removal".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control headlight auto leveling control unit installation".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control headlight auto leveling control unit setting".

Procedure completion

=>Go to Repair verification.

7. Instrument panel cluster replacement

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. instrument panel cluster removal".

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. instrument panel cluster installation".

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. instrument panel cluster setting".

Procedure completion

=>Go to Repair verification.

8. Repair verification

1) Reconnect all of the disconnected harness connectors.

2) Turn OFF the ignition switch.

3) Turn ON the ignition switch.

4) Check the headlight automatic leveling warning light. Does the headlight automatic leveling warning light illuminate for 3 seconds and then turn OFF?

Yes

The system is normal.

No

=>Go to Headlight automatic leveling warning light operation check.