E46 - AHL Control Unit For Adaptive Headlights: Notes
WARNING: This page does not describe the selected car, but rather 37 other vehicles, including the 2006 BMW 330Ci, 2006 BMW 325Ci, 2005 BMW M3, 2005 BMW 330xi, and 2005 BMW 330i. However, it is still accessible from the selected car via links, so may be relevant.
The AHL control unit is an identical component on all vehicle models with option 524.
The AHL control unit is adapted to the model concerned by coding at the end of the production line (the AHL control unit supplied by the manufacturer is coded for the E60).
The AHL control unit is the master control unit for the vertical and horizontal adjustment of the headlights. The AHL control unit sends the preset values for the position and the speed of the swivelling motion to the stepper motor controllers (in the headlight housing). The stepper motor controllers then control the stepper motors for the headlights accordingly.