Manual Mode

    See also:

    Diagnostics
    OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the v ...

    Engine Air Cleaner/Filter
    If the vehicle has a diesel engine, see “Pickup Models” under “Engine Air Cleaner/Filter” in the Duramax® Diesel Supplement for the correct inspection and replacement procedures. See Engine ...

    Engine Coolant Heater
    The engine heater can provide easier starting and better fuel economy during engine warm-up in cold weather conditions at or below −18°C (0°F). Vehicles with an engine heater should be plugged ...