See also:

Heated Mirrors
The vehicle may have heated mirrors: (Rear Window Defogger): Press to heat the mirrors. See “Rear Window Defogger” under Climate Control Systems  for more information. ...

If No Steam Is Coming from the Engine Compartment
If an engine overheat warning is displayed but no steam can be seen or heard, the problem might not be too serious. Sometimes the engine can get a little too hot when the vehicle: • Climb ...

Onstar.com
The website provides access to account information, manages the OnStar subscription, and allows viewing of videos of each service. Get subscription plan pricing and sign up for OnStar Vehicle ...