OnStar® Button Assembly Replacement
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2005 Isuzu Ascender, 2005 GMC Envoy XUV, 2005 GMC Envoy XL, 2005 GMC Envoy, and 2005 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The OnStar® ® button assembly located on the inside rearview mirror can not be serviced separately. Should the button assembly need to be replaced, the entire inside rearview mirror assembly will need to be replaced. Refer to Rearview Mirror Replacement in Stationary Windows.