2009 Chevrolet Silverado 2500 HD Extended Cab Owner's Manual - Page 128

Automatic Transmission Operation If the vehicle is a Two-mode Hybrid, see the Two-mode Hybrid manual for more information. Vehicles with an automatic transmission have 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. Heavy Duty 6-Speed Automatic Transmission Shown (Light Duty 6 Speed Similar) See "Range Selection Mode" later in this section. P (Park): This position locks the rear wheels. It is the best position to use when starting the engine because the vehicle cannot move easily. When parked on a hill, especially when the vehicle has a heavy load, you might notice an increase in the effort to shift out of P (Park). See Torque Lock (Automatic Transmission) under Shifting Into Park on page 2-52 for more information. Hydra-Matic® 4-Speed Automatic Transmission 2-28