TTY Users
OnStar has the ability to communicate to the deaf, hard&-ofhearing, or speech&-impaired customers while in the vehicle. The available dealer&-installed TTY system can provide in-vehicle access to all of the OnStar services, except Virtual Advisor and OnStar Turn&-by&-Turn Navigation.
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 ...
Tow/Haul Mode Light
For vehicles with the Tow/Haul Mode feature, this light comes on when the Tow/Haul Mode has been activated.
For more information, see Tow/Haul Mode on page 9‑42. ...
Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance.
However, if a customer wishes to write or e-mail GMC, the letter should be addressed to:
United States
GMC Customer Assistance ...





