2011 GMC Savana 2500 Passenger Owner's Manual - Page 240

9-32 Driving and Operating Grade Braking (Six Speed Automatic Transmission) The Grade Braking shift modes can be activated by pressing the TOW/HAUL button on the instrument panel. 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 Manual Mode on page 9‑31 for more information on the Range Selection Mode. Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades by automatically shifting to lower gears when the driver desires to slow the vehicle by applying the brake. This reduces wear on the braking system and increases control of the vehicle. Also see Trailer Towing on page 9‑50 for more information. Tow/Haul Mode Cruise Grade Braking (Six Speed Automatic Transmission) Cruise Grade Braking operates only while Cruise Control is engaged in Tow/Haul Mode. Cruise Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades in cruise control by automatically shifting to lower gears when the cruise set speed is exceeded. While in the Range Selection Mode, Cruise Grade Braking is not available. See Manual Mode on page 9‑31. 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 towing or hauling heavy loads. Turn the Tow/Haul Mode on and off by pressing the button, located to the right of the steering wheel on the instrument panel. When tow/ haul is on, a light on the instrument panel cluster will come on. See Tow/Haul Mode Light on page 5‑24 for more information. Also see "Tow Haul Mode" under Towing Equipment on page 9‑54 for more information.