Mechanical Reference Point
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.
There are two mechanical stops for each headlight. One of these mechanical stops is a reference point in case the zero-position sensor fails (it is determined during coding which of the two mechanical stops is the reference point).