2007 GMC Acadia Owner's Manual - Page 133

Tow/Haul Mode Your vehicle may have a Tow/Haul mode. The button to turn it on or off is located on instrument panel under the climate controls. Automatic Engine Grade Braking Automatic Engine 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, throttle position, and whether the brake pedal is being pressed, and determines when to keep the current vehicle speed or to slow down. The system will then automatically command downshifts that reduces the vehicle's speed, until the brake pedal is no longer being pressed. This indicates the desired vehicle speed has been reached. While in the Electronic Range Select (ERS) mode, grade braking is deactivated, allowing the driver to select a range and limiting the highest gear available. Grade braking is available for normal driving and in Tow/Haul mode. See Automatic Transmission Operation on page 129. Push the button to turn it on, push it again to deactivate the system. You can use this feature to assist when towing or hauling a heavy load. When Tow/Haul is activated the Tow/Haul symbol will come on the instrument panel cluster. See Tow/Haul Mode under Towing a Trailer on page 371 for more information. 133