Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle.
See also:
Ending a Call
Press to end a call. ...
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.
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Maintenance When Trailer Towing
The vehicle needs service more often when pulling a trailer.
See Maintenance Schedule on page 11‑3. Things that are especially important in trailer operation are automatic transmission fluid, e ...