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:
Folding Mirrors
For vehicles with manual folding mirrors, push the mirror toward the vehicle. Pull the mirror out to return to its original position.
For vehicles with power folding mirrors:
1. Press (A) to fold ...
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 communicat ...
Traction Control Operation
The TCS is part of the StabiliTrak system. Traction control limits wheel spin by reducing engine power to the wheels (engine speed management) and by applying brakes to each individual wheel (brake-tr ...