2008 Hummer H2 Owner's Manual - Page 114

Automatic Transmission Operation Your vehicle has a Hydra-Matic® 6L80 automatic transmission, and has an electronic shift position indicator within the instrument panel cluster. This display comes on when the ignition key is turned to the ON/RUN position. There are several different positions for the shift lever. {CAUTION: It is dangerous to get out of your vehicle if the shift lever is not fully in PARK (P) with the parking brake firmly set. Your vehicle can roll. Do not leave your vehicle when the engine is running unless you have to. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure your vehicle will not move, even when you are on fairly level ground, always set your parking brake and move the shift lever to PARK (P). See Shifting Into PARK (P) on page 2-41. If you are pulling a trailer, see Towing a Trailer on page 4-55. REVERSE (R): Use this gear to back up. Notice: Shifting to REVERSE (R) while your vehicle is moving forward could damage the transmission. The repairs would not be covered by your warranty. Shift to REVERSE (R) only after your vehicle is stopped. PARK (P): This position locks the rear wheels. It is the best position to use when you start your engine because your vehicle cannot move easily. When parked on a hill, especially when the vehicle has a heavy load, you may notice an increase in the effort to shift out of PARK (P). See Torque Lock (Automatic Transmission) under Shifting Into PARK (P) on page 2-41 for more information. 2-32