New for 2010

GM has dropped the long-running 6.0-liter V-8 engine from the Sierra lineup, leaving the powerful 6.2-liter V-8 for heavy towing needs. The rest of the Sierra's eight-cylinder lineup benefits from increased availability of its new six-speed transmission for regular and extended cab models equipped with the 5.3-liter V-8. Also, the 4.8-liter and 5.3-liter V-8 engines have been enhanced, with variable valve timing for improved emissions and better fuel economy.

Those with portable MP3 players can connect and play their music collections with the truck's audio system through a USB connection. Standard side curtain and side-impact airbags are welcome safety additions.

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    Starting the Vehicle
    With this feature the engine can be started from outside of the vehicle. 1. Aim the RKE transmitter at the vehicle. 2. Press and release . 3. Immediately after completing Step 2, press and hold ...

    Power Seat Adjustment
    A. Seat Adjustment Control B. Seatback Control C. Lumbar Control To adjust a power seat, if equipped: • Move the seat forward or rearward by sliding the control (A) forward or rearward. • R ...

    Charging System Light
    The charging system light comes on briefly when the ignition is turned on, but the engine is not running, as a check to show the light is working. The light turns off when the engine is started. ...