2010 GMC Terrain Owner's Manual - Page 249

Driving and Operating 8-41 Hill Start Assist (HSA) This vehicle has a Hill Start Assist (HSA) feature, which may be useful when the vehicle is stopped on a grade. This feature is designed to prevent the vehicle from rolling, either forward or rearward, during vehicle drive off. After driver completely stops and holds the vehicle in a complete standstill on a grade, HSA will be automatically activated. During the transition period between when the driver releases the brake pedal and starts to accelerate to drive off on a grade, HSA holds the braking pressure to ensure that there is no rolling back. The brakes will automatically release when the accelerator pedal is applied within the two second window. It will not activate if the vehicle is in a drive gear and facing downhill or if the vehicle is facing uphill and in R (Reverse). Ride Control Systems Traction Control System (TCS) The vehicle has a Traction Control System (TCS) that limits wheel spin. On a front-wheel-drive vehicle, the system operates if it senses that one or both of the front wheels are spinning or beginning to lose traction. On an All-Wheel-Drive (AWD) vehicle, the system will operate if it senses that any of the wheels are spinning or beginning to lose traction. When this happens, the system brakes the spinning wheel(s) and/or reduces engine power to limit wheel spin. The system may be heard or felt while it is working, but this is normal. The TCS/StabiliTrak warning light will flash to indicate that the traction control system is active. This warning light comes on if there is a problem with TCS, and the system will not limit wheel spin. Adjust your driving accordingly. TCS automatically comes on whenever the vehicle is started. To limit wheel spin, especially in slippery road conditions, the system should always be left on. But, TCS can be turned off if needed. Notice: Do not repeatedly brake or accelerate heavily when TCS is off. The vehicle's driveline could be damaged.