The driver can adjust the light range of his car by turning the knurled wheel for the manual headlight beam control system.
The headlights are then held in the current current setting.
The stepper motors are a component part of the headlights.
The left and right headlights are adjusted simultaneously.
The manual headlight beam throw control system receives its voltage from the light module as soon as the low beam light is switched on or the engine is running.
When the voltage supply is switched on, the headlight throw control system carries out a reference run in that it moves the headlights up and down to the relevant limit stop.The motors then assume the specified set position.
If the electronic circuitry integrated in the knurled wheel housing detects a defect, the control system is deactivated and this is signalled to the driver by the LWR symbol going out in the switch lighting.The figures on the knurled wheel remain illuminated by terminal 58g.
Since the two motors for beam throw control are switched in parallel, the electronics can only detect short-circuits but not a single line break.In this case the other headlight can still be moved.