If a manual headlight beam throw control facility is installed in the vehicle (identification feature): Knurled wheel for manual headlight beam throw control (on instrument panel) then this function is included in the LCM.
The LCM receives a voltage signal from the knurled wheel for manual headlight beam throw control and activates the motors in the headlights accordingly.
These motors are designed as stepper motors. They are connected in parallel. For this reason, although the electronic control can detect a short-circuit, it cannot detect a break in one of the two motors.
Adjustment via the knurled wheel is no longer possible in the case of fault.
The electronic control conducts a referencing run when the parking lights are switched on or when terminal 61 ("engine running") is activated.