See also:

Trailer Wiring Harness
The vehicle is equipped with one of the following wiring harnesses for towing a trailer or hauling a slide-in camper. ...

Onstar.com
The website provides access to account information, manages the OnStar subscription, and allows viewing of videos of each service. Get subscription plan pricing and sign up for OnStar Vehicle Diagnos ...

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. ...