2012 GMC Sierra Owner's Manual - Page 334

9-58 Driving and Operating Non-hybrid vehicles with StabiliTrak have a Trailer Sway Control (TSC) feature. See Trailer Sway Control (TSC) on page 9‑105. Non-hybrid vehicles with StabiliTrak have a Hill Start Assist (HSA) feature. See Hill Start Assist (HSA) on page 9‑54. Adding non‐dealer accessories can affect the vehicle's performance. See Accessories and Modifications on page 10‑3. Cruise Control When the brakes are applied, cruise control is turned off. For vehicles with an Allison or Hydra‐Matic 6‐speed automatic transmission, see "Grade Braking" under Tow/Haul Mode on page 9‑39 for an explanation of how cruise control interacts with the Range Selection Mode, tow/haul and grade braking systems. For vehicles with the StabiliTrak system that begins to limit wheel spin while you are using cruise control, the cruise control will automatically disengage. See StabiliTrak® System on page 9‑55. When road conditions allow the cruise control to be safely used again, it can be turned back on. { WARNING Cruise control can be dangerous where you cannot drive safely at a steady speed. So, do not use the cruise control on winding roads or in heavy traffic. Cruise control can be dangerous on slippery roads. On such roads, fast changes in tire traction can cause excessive wheel slip, and you could lose control. Do not use cruise control on slippery roads. For vehicles with cruise control, a speed of about 40 km/h (25 mph) or more can be maintained without keeping your foot on the accelerator. Cruise control does not work at speeds below about 40 km/h (25 mph). Locking Rear Axle Vehicles with a locking rear axle can give more traction on snow, mud, ice, sand, or gravel. It works like a standard axle most of the time, but when traction is low, this feature will allow the rear wheel with the most traction to move the vehicle.