Electronic Stability Program (ESP)

ELECTRONIC STABILITY PROGRAM

To determine whether the car is responding properly to cornering commands, ESP(R) 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(R) 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(R) 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).

HYDRAULIC BRAKE ASSIST

Brake Assist is programmed into the ESP(R) system. During a panic stop, a pressure sensor determines when the driver is doing so by measuring the brake pedal pressure application rate. A high rate of pedal pressure application causes the ESP(R) system to apply maximum available pressure to the brakes and the vehicle stops as quickly as available traction will allow.

TRACTION CONTROL

For information on the All-Speed Traction Control, Brakes - Operation.

HILL START ASSIST

The Hill Start Assist (HSA) system, programmed into the ESP system, is designed to assist the driver when starting a vehicle from a stop on a hill. HSA will maintain the level of brake pressure the driver applied for a short period of time after the driver takes his foot off of the brake pedal. If the driver does not apply the throttle during this short period of time the system will release brake pressure and the vehicle may roll down the hill. The system will release brake pressure in proportion to the amount of throttle applied as the vehicle starts to move in the intended direction of travel.