OnStar Button Assembly Replacement
WARNING: This page is about a different car, the 2002 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
The OnStar® Buttons are an integral part of the rear view mirror assembly. If the button malfunctions, you must replace the rear view mirror assembly. Refer to REARVIEW MIRROR REPLACEMENT (UE1) .