See also:

Customer Assistance for Text Telephone (TTY) Users (U.S. and Canada)
To assist customers who are deaf, hard of hearing, or speech impaired and who use Text Telephones (TTYs), GMC has TTY equipment available at its Customer Assistance Center. Any TTY user can communicat ...

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 obstac ...

Hill Start Assist (HSA)
This vehicle has 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, either forward or rearward ...