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 ...

Parking Brake
To set the parking brake, hold the regular brake pedal down, then push the parking brake pedal down. If the ignition is on, the brake system warning light will come on. See Brake System Warning ...

Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...