Using the “Dial” or “Call” Command
1. Press and hold 
for two seconds.
2. Say “Dial” or “Call.” 3. Say the entire number without pausing, or say the name tag.
Once connected, the person called will be heard through the audio speakers.
See also:
Vehicle Overview
Though gas mileage ratings for GM's full-size SUVs are impressive among their
competitive set, they aren't likely to bring smiles to anyone at the pump; their
combined ratings still linger in the ...
Online Owner Center
Manage your vehicle (U.S.) at gmc.com. Click on “Owners,” then “Manage My GMC/Owners Login.”
Information and services customized for your specific vehicle — all in one convenient place.
...
Safety Belts
This section of the manual describes how to use safety belts properly. It also
describes some things not to do with safety belts.
WARNING
Do not let anyone ride where a safety belt cannot be worn ...