See also:

Adjusting the Brightness and Contrast of the Screen
To adjust the brightness and contrast of the screen, press the MENU button while the rear vision camera image is on the display. Any adjustments made will only affect the rear vision camera screen. ...

Ending a Call
Press to end a call. ...

Using Voice Commands During a Planned Route
Cancel Route 1. Push X. System responds: “OnStar ready,” then a tone. Say “Cancel route.” System responds: “Would you like to cancel route directions to your destination?” 2. Say “Ye ...