See also:

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 ...

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehic ...

Manual Trailer Brake Apply
The Manual Trailer Brake Apply Lever is located on the Trailer Brake Control Panel and is used to apply the trailer’s electric brakes independent of the vehicle’s brakes. This lever is used in th ...