2012 GMC Sierra Owner's Manual - Page 308

9-32 Driving and Operating The shift lock release is always functional except in the case of an uncharged or low voltage (less than 9 volt) battery. If the vehicle has an uncharged battery or a battery with low voltage, try charging or jump starting the battery. See Jump Starting on page 10‑88 for more information. To shift out of P (Park) use the following: 1. Apply the brake pedal. 2. Move the shift lever to the desired position. If you still are unable to shift out of P (Park): 1. Ease the pressure on the shift lever. 2. While holding down the brake pedal, press the shift lever all the way into P (Park). 3. Move the shift lever to the desired position. If you are still having a problem shifting, then have the vehicle serviced soon. When you are ready to drive, move the shift lever out of P (Park) before you release the parking brake. If torque lock does occur, you may need to have another vehicle push yours a little uphill to take some of the pressure from the parking pawl in the transmission, then you will be able to pull the shift lever out of P (Park). Parking over Things That Burn { WARNING Things that can burn could touch hot exhaust parts under the vehicle and ignite. Do not park over papers, leaves, dry grass, or other things that can burn. Shifting out of Park This vehicle is equipped with an electronic shift lock release system. The shift lock release is designed to: . Prevent ignition key removal unless the shift lever is in P (Park) with the shift lever button fully released. Prevent movement of the shift lever out of P (Park), unless the ignition is in ON/RUN or ACC/ ACCESSORY and the regular brake pedal is applied. Active Fuel Management® Vehicles with V8 engines may have Active Fuel Management™. This system allows the engine to operate on either all or half of its cylinders, depending on the driving conditions. .