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 ...

Potential Issues
Some OnStar services are disabled after five days. OnStar cannot perform Remote Door Unlock or Stolen Vehicle Assistance after the vehicle has been off continuously for five days. After five days, ...

Turning the RVC System On or Off
To turn off the RVC system, press and hold , located on the inside rearview mirror, until the left indicator light turns off. The RVC display is now disabled. To turn the RVC system on, press and h ...