Electronic Stability Control (ESC) uses the speed sensors on each wheel and the ability to brake individual wheels that are the basis of anti-lock brakes. ESC adds a control unit that monitors steering wheel angle and vehicle rotation around the vehicle's vertical axis. This unit uses the steering and rotation information to detect that the vehicle is about to travel in a direction different from the one indicated by the steering wheel position. Then ESC automatically brakes the appropriate wheel to help the driver maintain control. In many cases engine power also is reduced.
NOTE: All model year 2012 vehicles under 10,000 lb gross vehicle weight are equipped with ESC.