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:
Horn
To sound the horn, press the center pad on the steering wheel. ...
Muting a Call
During a call, all sounds from inside the vehicle can be muted so that the person
on the other end of the call cannot hear them.
To mute a call, press , and then
say “Mute Call.”
To cancel m ...
OnStar Mobile App
With an iPhone® or Android™-based mobile device, an OnStar mobile app can be downloaded. The vehicle can be remote started, if equipped, or the doors can be unlocked from anywhere there is cell pho ...