See also:

All-Wheel Drive
Vehicles with this feature always send engine power to all four wheels. It is fully automatic, and adjusts itself as needed for road conditions. When using a compact spare tire on an AWD vehicle, the ...

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 Calling ar ...

Range Selection Mode (Allison® Transmission or Hydra-Matic® 6-Speed Transmission)
The vehicle may have a Range Selection Mode. The Range Selection Mode helps control the vehicle's transmission and vehicle speed while driving down hill or towing a trailer by letting you select a d ...