Lost Communication with Headlamp Leveling Control Module
The vehicle network has lost the headlamp leveling controller. Automatic leveling is disabled and the lamps stay in a default position; on many vehicles the headlight warning comes on.
Affected components
- Headlamp leveling module
- Can bus wiring
Common causes
- High likelihood: Leveling module unpowered
- Low likelihood: Gateway module routing CAN messages incorrectly
- Low likelihood: CAN terminating resistor (120 Ω) drifted out of spec
Possible symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.