See also:

Muting a Call
During a call, all sounds from inside the vehicle can be muted so that the person on the other end of the call cannot hear them. To mute a call, press , and then say “Mute Call.” To cancel mute, ...

Heated Mirrors
The heated outside rearview mirrors turn on when the rear window defogger is on. (Rear Window Defogger): This button is on the climate control panel. See “Rear Window Defogger” under Dual Automa ...

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the v ...