Power Mirror System Controls
WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
The outside rearview mirror switch is a four position directional switch: Up, Down, Left and Right.
The mirror select switch is a three position switch: L for left, Off for none, and R for right.