Cars equipped with Xenon lights shall, according to law, have a system for automatic length control to even out not only static loads but also dynamic loads that occur when braking and accelerating. This is to avoid blinding on-coming cars. The control unit for light beam length control uses several different parameters, and actuators, to regulate the headlights' setting.
For the following basic setting, the control function is turned off and the headlights are controlled to adjusting position.
Test conditions:
Ignition on.
Low beams on.
Vehicle unloaded without driver or passengers.
Position the vehicle on a level surface with the wheels facing straight forward.
If headlight level control is installed, set it to position 0.
Procedure:
Start the function.
The headlights are now in service mode and shall be adjusted according to specifications using suitable equipment.
The function is done.
If the function fails, check the test conditions and repair any faults.