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 ...

Shifting out of Park
The vehicle is equipped with an electronic shift lock release system. The shift lock release is designed to: • Prevent ignition key removal unless the shift lever is in P (Park) with the shift lev ...

Storing and Deleting Phone Numbers
The system can store up to 30 phone numbers as name tags in the Hands-Free Directory that is shared between the Bluetooth and OnStar systems, if equipped. The following commands are used to delete an ...