See also:

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 ...

Auxiliary Devices
The vehicle may have a 3.5mm (1/8 in) auxiliary input jack located on the lower right side of the faceplate and for vehicles with a USB port, it is located in the instrument panel storage area. ...

Lockout Protection
If the driver side power door lock switch is pressed when the driver door is open and the key is in the ignition, all of the doors will lock and then the driver door will unlock. If the passenger sid ...