Electronic Stability Program

Electronic Stability Program (ESP) control module is connected to engine and transmission control modules over CAN data bus. ESP control module is constantly supplied with current data on engine torque, accelerator pedal position and transmission ratio. Inputs from yaw sensor, 4 wheel speed sensors, steering angle sensors, ESP brake pressure sensor, brakelight switch and lateral acceleration sensor are monitored by ESP control module. If values exceed pre-programmed limits, appropriate solenoid valves, charging pump and high pressure pump/return pump in hydraulic unit are actuated by the ESP control module.

Commands to ME-SFI and EGS control modules are sent over CAN data bus to reduce engine torque and transmission downshift if necessary. ESP functions can be switched off using ESP switch located on center console. With ESP switch in OFF position, warning light in speedometer will remain illuminated but will flash if one or both drive wheels spin.

Electronic Stability Program (ESP) records rotary movement of vehicle about vertical axis (skid movement). A hollow steel cylinder (measuring element) is made to vibrate at a particular frequency by piezioelements. 4 pairs of piezioelements are attached to the cylinder opposite one another in each case. Depending on the rotary movement of vehicle, vibration patterns occurring between the piezioelements are recorded as a measure of the yaw of the vehicle.