If your vehicle has an automatic transmission, it may have a Tow/Haul mode. If your vehicle has an Allison Transmission® see "Tow/Haul Mode (Allison Transmission®) following. 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.

The selector button is located on the end of the shift lever. Turn the Tow/Haul on and off by pressing the button. When the Tow/Haul is on, a light on the instrument panel cluster will come on.

See Tow/Haul Mode Light for more information.

If your vehicle is equipped with the Performance Package-Enhanced Towing, activating the manual selectable ride will adjust the shock absorber characteristics to enhance the ride and handling of the vehicle for towing or hauling heavy loads.

Also see Tow Haul Mode under Towing a Trailer for more information.

If your vehicle has an Allison Transmission®, it may have a Tow/Haul mode. 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.

The selector button is located on the end of the shift lever. Turn the Tow/Haul on and off by pressing the button. When the Tow/Haul is on, a light on the instrument panel cluster will come on.

See Tow/Haul Mode Light for more information.

Also see "Tow Haul Mode" under Towing a Trailer for more information.

Grade Braking and Cruise Grade Braking assists when driving on a downhill grade. It maintains the vehicle's speed by automatically implementing a shift schedule that uses the engine and the transmission to slow the vehicle. This reduces wear on the brakes system and increases control of the vehicle. The system constantly monitors the vehicle's speed, acceleration, engine torque, and brake pedal usage. It detects when the truck is on a downhill grade and the driver's desire to slow down by pressing the brake.

Cruise Grade Braking is available on the 6.6L Duramax® diesel engine. Cruise Grade Braking monitors a vehicle's cruise state, engine torque, acceleration, vehicle speed, and the cruise set speed. Using this information, it detects when the truck is accelerating on a downhill grade and will automatically downshift to slow the vehicle if it exceeds the cruise set speed by a certain amount.

See Cruise Control for more information.

The Tow/Haul mode and Grade Braking shift modes can be activated by pressing the button on the end of the shift control stalk. If your vehicle has the Duramax® diesel Engine or the 8.1L VORTEC™ gasoline engine, Grade Braking is only available while the Tow/Haul Mode is selected. While in the Range Selection Mode, Grade Braking is deactivated allowing the driver to select a desired range of gears.

See Automatic Transmission Operation for more information.

Also see Towing a Trailer for more information.