2007 GMC Acadia Owner's Manual - Page 136

Leaving Your Vehicle With the Engine Running Torque Lock If you are parking on a hill and you do not shift your transmission into PARK (P) properly, the weight of the vehicle may put too much force on the parking pawl in the transmission. You may find it difficult to pull the shift lever out of PARK (P). This is called "torque lock." To prevent torque lock, set the parking brake and then shift into PARK (P) properly before you leave the driver's seat. To find out how, see Shifting Into Park (P) on page 135. When you are ready to drive, move the shift lever out of PARK (P) before you release the parking brake. If torque lock does occur, you may need to have another vehicle push your vehicle 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 PARK (P). {CAUTION: It can be dangerous to leave your vehicle with the engine running. Your vehicle could move suddenly if the shift lever is not fully in PARK (P) 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 your vehicle with the engine running. If you have to leave your vehicle with the engine running, be sure your vehicle is in PARK (P) and your parking brake is firmly set before you leave it. After you have moved the shift lever into PARK (P), hold the regular brake pedal down. Then, see if you can move the shift lever away from PARK (P) without first pushing the button. If you can, it means that the shift lever was not fully locked in PARK (P). 136