Deactivation of adaptive headlights function in response to system faults
If a system fault occurs, the indicator lamp flashes. The adaptive headlights function is deactivated as follows:
· If the stepper motors are still functional, the headlights are returned to the straight-ahead position.
· If one of the headlights has jammed in a position in which it could dazzle oncoming vehicles, the headlight concerned is switched off as soon as the vehicle is stationary. The front fog lamps are switched on in order to ensure a minimum level of illumination. The headlight is not switched off while the vehicle is in motion.

Interesting... chris, is it safe to assume that this is not happening in your case? when you are driving, and the light is stuck in right position, the light does not shut off when you come to a stop at stop sign or traffic light? and, if you had the fog lights off, the fog light does not come on automatically, does it?...

If the xenon light remains on, the fog light is not coming on, it indicates that the vertical stepping motor is working fine (no blinding of the oncoming traffic)...
Since the headlight is not returning to the "park" position, it might be the stepper motor for horisontal adjustment is malfunctioning...

This brings us back to the mechanical issue...

There are several possible issues with the mechanical malfunction:

1. the stepper motor is defective - replace motor
2. the gears are disengaged, and need to be re-engaged - it could be that the manual adjustment of the headlight is adjusted outside of the mechanical limits of reach of the motor gears, like someone turned the adjustment knob too far and the gear fell off the worm drive
3. the gears outside of the moter are actually broken, and will need to be replaced - chances are, the headlight would ned to be opened in order to fix/replace the worm drive and the gears...

To get started on this, the headlight will need to come off the car...

do you know how to do this?