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 communicate with GMC by dialing:
1-800-462-8583. TTY users in Canada can dial 1-800-263-3830.
See also:
Driving with the Blind Spot Mirror
Actual Mirror View
1. When the approaching vehicle is a long distance away, the image in the main
mirror is small and near the inboard edge of the mirror.
2. As the vehicle gets closer, the imag ...
Engine Oil Life System
The engine oil life system calculates engine oil life based on vehicle use and
displays the CHANGE ENGINE OIL SOON message when it is time to change the engine
oil and filter. The oil life system ...
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 ...





