2012 GMC Sierra Owner's Manual - Page 315

Driving and Operating the plus/minus button located on the steering column lever is used to change to the gear. Grade Braking is not available when Range Selection Mode is active. See Tow/Haul Mode on page 9‑39. While using Range Selection Mode, Cruise Control and the Tow/Haul Mode can be used. If the vehicle has an exhaust brake, it can also be used, but will not automatically downshift the transmission. See Exhaust Brake in the Duramax Diesel supplement. Notice: Spinning the tires or holding the vehicle in one place on a hill using only the accelerator pedal may damage the transmission. The repair will not be covered by the vehicle warranty. If you are stuck, do not spin the tires. When stopping on a hill, use the brakes to hold the vehicle in place. 9-39 Low Traction Mode If your vehicle has the Allison Transmission, or the Hydra-Matic 6-Speed Automatic Transmission, it has a Low Traction Mode that can assist in vehicle acceleration when road conditions are slippery, such as with ice or snow. While the vehicle is at a stop, select the second gear range using Range Selection Mode. This will limit torque to the wheels after it detects wheel slip, preventing the tires from spinning. 6-Speed Automatic Transmission Vehicles with an automatic transmission have a Tow/Haul Mode. The Tow/Haul Mode adjusts the transmission shift pattern to reduce shift cycling, providing increased performance, vehicle control, and transmission cooling when driving down steep hills or Mountain grades, towing, or hauling heavy loads. The selector button is located on the end of the shift lever. Turn the Tow/Haul Mode on and off by pressing the button. When the Tow/Haul Mode is enabled, a light on the instrument panel cluster will come on. Tow/Haul Mode 4-Speed Automatic Transmission