Circuit/System Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The Driver Door Module (DDM) or Passenger Door Module (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 vertical control circuit and voltage or ground is supplied through the mirror motor common control circuit.
Horizontal controls operate in the same manner with the mirror motor horizontal control circuit supplying voltage or ground and the mirror motor common control circuit suppling voltage or ground to the mirror horizontal motor when the mirror is commanded right and left.