Power Mirror System Controls
WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The outside rearview mirror switch is a 4 position directional switch: Up, Down, Left and Right.
The mirror select switch is a 3 position switch: L, Off and R.