Power Mirror Switch: Operation
WARNING: This page is about a different car, the 2002 Dodge Intrepid, 2002 Chrysler Intrepid, 2002 Chrysler Concorde, and 2002 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.
Position sensing potentiometers are built into each mirror's vertical and horizontal motor assembly. These potentiometers provide a sense voltage to the MHSMM that indicates where the actual location of each mirror is. If a memory position is set, the values of the potentiometers at that location are stored in memory.