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 ...

Grade Braking (6-Speed Automatic Transmission)
The Grade Braking shift modes can be activated by pressing the button on the end of the shift control lever. While in Range Selection Mode, Grade Braking is deactivated allowing the driver to select ...

Adjustable Throttle and Brake Pedal
On vehicles with this feature, you can change the position of the throttle and brake pedals. No adjustment to the pedals can be made when the vehicle is in R (Reverse) or while using cruise control. ...