2012 Chevrolet Tahoe Owner's Manual - Page 315

Driving and Operating 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 9‑35 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 Equipment on page 9‑79 for more information. 9-37 Drive Systems Four-Wheel Drive (Two Speed Automatic Transfer Case) If the vehicle has four-wheel drive, you can send the engine's driving power to all four wheels for extra traction. Read the following before using four-wheel drive. Notice: Driving on clean, dry pavement in Four-Wheel Drive High or Four-Wheel Drive Low for an extended period of time may cause premature wear on the vehicle's powertrain. Do not drive on clean, dry pavement in Four-Wheel Drive High or Four-Wheel Drive Low for extended periods of time. While driving on clean dry pavement and during tight turns, you may experience a vibration in the steering system. When Tow/Haul Mode is selected the tow/haul indicator light will come on. See Tow/Haul Mode Light on page 5‑24. 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 Continuous Damping Control (CDC) on page 9‑51. 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.