2009 Chevrolet Express Van Owner's Manual - Page 207

For your safety, the system can only be disabled when the vehicle speed is less than 20 mph (32 km/h). Three chimes will be heard and the StabiliTrak light comes on. To turn on the StabiliTrak system, press the StabiliTrak button again. StabiliTrak will automatically turn back on when the vehicle speed exceeds 20 mph (32 km/h). One chime is heard and the StabiliTrak light will turn off. When the StabiliTrak system has been turned off, system noises may still be heard as a result of the brake-traction control coming on. It is recommended to leave the system on for normal driving conditions, but it may be necessary to turn the system off if the vehicle is stuck in sand, mud, ice or snow, and you want to "rock" the vehicle to attempt to free it. See If Your Vehicle is Stuck in Sand, Mud, Ice, or Snow on page 4-18. StabiliTrak System Operation The StabiliTrak system is normally on, except when the system is initializing or has been disabled with the StabiliTrak button. The StabiliTrak system will automatically activate to assist the driver in maintaining vehicle directional control in most driving conditions. When activated, the StabiliTrak system may reduce engine power to the wheels and apply braking to individual wheels as necessary to assist the driver with vehicle directional control. If cruise control is being used when StabiliTrak activates, the cruise control automatically disengages. The cruise control can be re-engaged when road conditions allow. See Cruise Control on page 3-9. The StabiliTrak system may also turn off automatically if it determines that a problem exists with the system. If the problem does not clear itself after restarting the vehicle, see your dealer/retailer for service. 4-7