See also:

Window Lockout
(Window Lockout): If a crew cab or extended cab vehicle has power windows, the driver door power window switch has a lockout feature. This feature prevents the rear windows from operating, except fr ...

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 ...

Navigation
OnStar navigation requires the Directions and Connections service plan. Push to receive directions or have them sent to the vehicle navigation screen. Destinations can also be forwarded to the vehic ...