2010 Chevrolet Suburban 2500 Owner's Manual - Page 180

When Tow/Haul mode is selected the Tow/Haul indicator light will come on. The Tow/Haul mode works with the Autoride ® feature, if the vehicle has this, to enhance the ride when trailering or with a loaded vehicle. See Autoride® on page 5‑50. Grade Braking (Hydra-Matic® 6-Speed Automatic Transmission) The Grade Braking shift modes can be activated by pressing the button on the end of the shift control lever. While in Range Selection Mode , Grade Braking is deactivated allowing the driver to select a desired range of gears. Grade Braking is only active while the Tow/Haul Mode is selected and you are not in the Range Selection Mode. See "Tow/Haul Mode listed previously and Automatic Transmission Operation on page 3‑33 for more information on the Range Selection Mode. Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades by automatically implementing a shift schedule that utilizes the engine and transmission to slow the vehicle. This reduces wear on the braking system and increases control of the vehicle. Grade Braking monitors vehicle speed, acceleration, engine torque and brake pedal usage. Using this information, it detects when the truck is on a downhill grade and the driver desires to slow the vehicle by pressing the brake. Also see Towing a Trailer on page 5‑50 for more information. 3-40