See also:

TTY Users
OnStar has the ability to communicate to the deaf, hard-of-hearing, or speech-impaired customers while in the vehicle. The available dealer-installed TTY system can provide in-vehicle access to all of ...

Hill Start Assist (HSA)
Non-hybrid vehicles with StabiliTrak have a Hill Start Assist (HSA) feature, which may be useful when the vehicle is stopped on a grade. This feature is designed to prevent the vehicle from rolling, ...

How the System Works
URPA comes on automatically when the shift lever is moved into R (Reverse). A single tone sounds to indicate the system is working. URPA operates only at speeds less than 8 km/h (5 mph). An obstacle ...