OnStar®

If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. See OnStar Overview on page 14‑1 for more information.

    See also:

    Danger, Warnings, and Cautions
    Warning messages found on vehicle labels and in this manual describe hazards and what to do to avoid or reduce them. Danger indicates a hazard with a high level of risk which will result in serious i ...

    Powertrain details
    The GMC Sierra All Terrain HD concept is propelled by the new, production 6.6L Duramax turbo-diesel V-8 and Allison 1000 six-speed automatic transmission powertrain combination offered in the 2011 ...

    Roof
    Sunroof The ignition must be in ON/RUN or ACC/ACCESSORY to operate the sunroof and power sunshade. See Retained Accessory Power (RAP) on page 9‑20. The vehicle may have a sunroof over the fro ...