Vehicle and Power Issues
OnStar services require a vehicle electrical system, wireless service, and GPS satellite technologies to be available and operating for features to function properly. These systems may not operate if the battery is discharged or disconnected.
See also:
Leaving the Vehicle With the Engine Running
WARNING
It can be dangerous to leave the vehicle with the engine running. The vehicle
could move suddenly if the shift lever is not fully in P (Park) with the parking
brake firmly set. And, if yo ...
Retained Accessory Power (RAP)
These vehicle accessories can be used for up to 10 minutes after the engine is
turned off:
○ Audio System
○ Power Windows
○ Sunroof (if equipped)
Power to the audio system will ...
Tachometer
The tachometer displays the engine speed in revolutions per minute (rpm). For a description of how Grade Braking affects vehicle speed while the Tow/Haul Mode is activated, see Tow/Haul Mode on page 9 ...