Reactivation for Subsequent Owners
Push 
and follow the prompts to speak to an Advisor as soon as possible after acquiring the vehicle.
The Advisor will update vehicle records and will explain the OnStar service offers and options available.
See also:
Overview
The GMC Sierra All Terrain HD concept is an exploration of heavy-duty truck
capability combined with greater off-road versatility. It is highlighted by a
bold exterior design, enhanced all-terrain ...
Recommended Transfer Case Settings
You can choose among four driving settings:
Indicator lights in the dial show which setting you are in. The indicator lights will come on briefly when you turn on the ignition and one will stay on. ...
A Transformative Engine
You might be thinking, "How can GMC's compact pickup feel like a muscle car?"
Well, there's more to it than stuffing a 5.3-liter V-8 under the hood, but that
engine goes a long way towar ...