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) Connect the scan tool.
2) Turn OFF the ignition switch.
3) Start the engine and operate the vehicle.
4) Observe the DTC information with a scan tool. Is a DTC set?
Yes
=>Go to EHCU DTC check.
No
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".
3. EHCU DTC check
4. ECM DTC check
1) Observe the EHCU DTC information with a scan tool. Is a DTC set?
Yes
Go to the applicable DTC diagnosis.
No
=>Go to Headlight auto leveling control unit replacement.
5. Headlight auto leveling control unit replacement
Note
- Perform initialization of the vehicle height values after replacing the headlight auto leveling control unit.
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.
6. Repair verification
1) Clear the DTC with a scan tool.
2) Turn OFF the ignition switch.
3) Start the engine and operate the vehicle.
4) Observe the DTC information with a scan tool.