Circuit/System Description
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The Driver Door Switch (DDM) or Passenger Door Switch (PDM) controls the mirror horizontal and vertical motors through the use of bi-directional motor controls. When the mirror is commanded up and down, voltage or ground is supplied to the mirror vertical motor through the mirror motor up/down control circuit and voltage or ground is supplied through the mirror motor common circuit.
Horizontal controls operate in the same manner with the mirror motor left/right control circuit supplying voltage or ground and the mirror motor common circuit suppling voltage or ground to the mirror horizontal motor when the mirror is commanded right and left.