2010 Hummer H3 Owner's Manual - Page 222

9-38 Driving and Operating If you have to leave the vehicle with the engine running, be sure the vehicle is in P (Park) and the parking brake is firmly set before you leave it. After you have moved the shift lever into P (Park), hold the regular brake pedal down. Then, see if you can move the shift lever away from P (Park) without first pressing the shift lever button. If you can, it means that the shift lever was not fully locked into P (Park). Torque lock is when the weight of the vehicle puts too much force on the parking pawl in the transmission. This happens when parking on a hill and shifting the transmission into P (Park) is not done properly and then it is difficult to shift out of P (Park). To prevent torque lock, set the parking brake and then shift into P (Park). To find out how, see "Shifting Into P (Park)" listed previously. If torque lock does occur, your vehicle may need to be pushed uphill by another vehicle to relieve the parking pawl pressure, so you can shift out of P (Park). Leaving Your Vehicle With the Engine Running (Automatic Transmission) { WARNING It can be dangerous to leave the vehicle with the engine running. The vehicle could move suddenly if the shift lever is not fully in P (Park) with the parking brake firmly set. And, if you leave the vehicle with the engine running, it could overheat and even catch fire. You or others could be injured. Do not leave the vehicle with the engine running. 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, and 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. .