See also:

Tachometer
The tachometer displays the engine speed in revolutions per minute (rpm). ...

Playing a CD or MP3 CD (Radio with CD and Touchscreen)
Press the TUNE/MENU knob to display the CD Menu. Shuffle: Select to play the tracks randomly rather than in sequence. Select again to stop shuffle. A checkmark indicates shuffle is on. Track List: ...

How OnStar Service Works
Automatic Crash Response, Emergency Services, Crisis Assist, Stolen Vehicle Assistance, Vehicle Diagnostics, Remote Door Unlock, Roadside Assistance, Turn-by-Turn Navigation, and Hands-Free ...