Electronic Stability Program (ESP)

ELECTRONIC STABILITY PROGRAM


DESCRIPTION
The ESP system enhances directional control and stability of the vehicle under various driving conditions. ESP corrects for over/under steering of the vehicle by applying the brake of the appropriate wheel to assist in counteracting the over/under steer condition. Engine power may also be reduced to help the vehicle maintain the desired path. ESP uses sensors in the vehicle to determine the vehicle path intended by the driver and compares it to the actual path of the vehicle. When the actual path does not match the intended path, ESP applies the brake of the appropriate wheel to assist in counteracting the oversteer or understeer condition
^ Oversteer - when the vehicle is turning more than appropriate for the steering wheel position.
^ Understeer - when the vehicle is turning less than appropriate for the steering wheel position.

The ESP/TCS Indicator Light located in the instrument cluster, starts to flash as soon as the tires lose traction and the ESP system becomes active. The ESP/TCS Indicator Light also flashes when TCS is active.

OPERATION
To determine whether the car is responding properly to cornering commands, ESP uses steering wheel angle, yaw (turning) rate and lateral acceleration sensors (combined into Dynamics Sensor). Using signals from these sensors, in addition to individual wheel speed sensor signals, the system determines appropriate brake and throttle actions. Once initiated, ESP operates much like All-Speed Traction Control, except that the goal is directional stability. If the vehicle yaw response, or rate of turning, is inconsistent with the steering angle and vehicle speed indications, the ESP system applies the brakes and, if necessary closes the throttle, to restore control. This occurs whether the vehicle is turning too rapidly (oversteering) or not rapidly enough (understeering).