A6C9
ModerateA6C9 — Adaptive Headlight Swivel Motor: Malfunction
Description
What the Code Means
Code A6C9 logs a fault in the adaptive headlight swivel motor or its control circuit. The headlight control module monitors the swivel mechanism and sets the fault when the mechanism doesn't respond or works incorrectly. Typical causes are a seized motor, damaged wiring, or a failed module.
With this fault, the adaptive headlights stop swiveling with the steering. Cornering illumination gets worse, and visibility drops in the dark.
Symptoms
Symptoms
- Yellow Adaptive Malfunction warning on the instrument cluster.
- Headlights locked in the straight-ahead position.
- No light swivel when cornering.
- Code A6C9 stored in the control module memory (DME).
Causes and fixes
Diagnosis and Repair
- Read and confirm code A6C9 with ISTA.
- Check the headlight control module for power and ground.
- Inspect the wiring harness for damage and corrosion.
- If the headlight control module is faulty, replace it with an original
63117354974. - Code the new module to the vehicle's VIN with NCS Expert or ISTA.
Possible secondary damage
Secondary Problems
- If you ignore the fault, the swivel motor can seize completely — then you'll need to replace the whole headlight assembly (the expensive repair option).
- Reduced visibility at night while cornering raises the risk of a crash, so don't put off diagnosis.