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 mute, press , and then say “Un-mute call.”
See also:
Roadside Assistance Program
U.S.: 1-888-881-3302
TTY Users (U.S.): 1-888-889-2438
Canada: 1-800-268-6800
Mexico: 01-800-466-0801
As the owner of a new GMC, you are automatically enrolled in the Roadside Assistance program.
...
Following Distance
Stay at least twice as far behind the vehicle ahead as you would when driving the vehicle without a trailer.
This can help to avoid situations that require heavy braking and sudden turns. ...
Roadside Assistance Program (U.S. and Canada)
For U.S.-purchased vehicles, call 1-888-881-3302; (Text Telephone (TTY): 1-888-889-2438).
For Canadian-purchased vehicles, call 1-800-268-6800.
Service is available 24 hours a day, 365 days a year. ...