Three-Way Calling
Three-way calling must be supported on the cell phone and enabled by the wireless service carrier.
1. While on a call, press 
.
2. Say “Three-way call.” 3. Use the dial or call command to dial the number of the third party to be called.
4. Once the call is connected, press to link all callers together.
See also:
USB Support
The USB connector is located on the instrument panel or in the center console, and uses the USB 2.0 standard. ...
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.
...
Using Cruise Control on Hills
How well the cruise control works on hills depends on the vehicle speed, the load, and the steepness of the hills. When going up steep hills, pressing the accelerator pedal may be necessary to maintai ...