Description of ESC Control: Notes
ESC system features ABS/EBD, TCS and AYC functions.
ABS/EBD function: The ECU converts the active sensor signal (current shift) from four wheel sensors into square waves. By using the input of above signals, the ECU calculates the vehicle speed and acceleration & deceleration of the four wheels. Also, the ECU determines actuation of the ABS/EBD.
TCS function prevents the wheel slip in driving direction by adding the brake pressure and reducing engine torque via CAN communication. TCS function uses the wheel speed sensor signal to determine the wheel slip related to ABS function.
AYC function prevents unstable maneuver of the vehicle. To determine the vehicle maneuver, AYC function uses the maneuver sensor signals (Yaw Rate Sensor, Lateral Acceleration Sensor, Steering Wheel Angle Sensor).
If vehicle maneuver is unstable (Over Steer or Under Steer), AYC function applies brake pressure on certain wheel, and sends engine torque reduction signal via CAN.
After the key-on, the ECU continuously diagnoses the system failure (self-diagnosis). If the system failure is detected, the ECU informs driver of the system failure through the BRAKE/ABS/ESC warning lamp (fail-safe warning).