VEHICLE STABILITY CONTROL SYSTEM SYSTEM DESCRIPTION


  1. FUNCTION DESCRIPTION


    1. ABS (Anti-lock Brake System)

      The ABS helps prevent the wheels from locking when the brakes are applied firmly or when braking on a slippery surface.

    2. EBD (Electronic Brake force Distribution)

      The EBD control utilizes ABS, and performs proper brake force distribution between the front and rear wheels in accordance with driving conditions.

      When braking while cornering, it also controls the brake forces of the right and left wheels, helping to maintain vehicle behavior.

    3. BA (Brake Assist)

      The primary purpose of the brake assist system is to provide auxiliary brake force to assist a driver who cannot generate a large enough brake force during emergency braking, thus helping to maximize the braking performance of the vehicle.

    4. TRC (Traction Control)

      The TRC system helps prevent the drive wheels from slipping when the driver depresses the accelerator pedal excessively when starting off or accelerating on a slippery surface.

    5. VSC (Vehicle Stability Control)

      The VSC system helps prevent the vehicle from slipping sideways as a result of strong front or rear wheel skid during cornering.

    6. VSC (Cooperative Control with EPS)

      The cooperative control with the power steering ECU provides steering assistance in accordance with the operating conditions of the vehicle.

    7. Hill-start Assist Control

      When starting uphill, this control maintains the brake hydraulic pressure on all 4 wheels, in order to momentarily prevent from descending backward.

  2. FUNCTION OF COMPONENTS

    Component Function
    Speed sensor Detects the wheel speed and sends the signal to the skid control ECU.
    Yaw rate and acceleration sensor (yaw rate sensor)

    • The acceleration sensor is built into the yaw rate sensor.

    • The acceleration sensor measures the capacitance of the capacitor, which changes the distance between the electrodes depending on the G force which occurs when the vehicle is accelerated, and converts the measured value into electrical signals.

    • The yaw rate sensor detects the angular velocity (yaw rate) of the vehicle based on the amount and direction of the deflection of the piezoelectric ceramic.

    • The yaw rate sensor sends signals to the skid control ECU and related systems via CAN communication.
    Steering angle sensor (spiral with sensor cable sub-assembly)

    • Installed in the spiral with sensor cable sub-assembly.

    • Detects the steering amount and direction and sends the signals to the skid control ECU via CAN communication.
    Stop light switch assembly Detects the brake pedal condition and inputs the status to the skid control ECU.
    Master cylinder pressure sensor

    • Detects the fluid pressure in the master cylinder.

    • Housed in the brake actuator assembly.
    Skid control ECU

    • Housed in the brake actuator assembly.

    • Processes the signals sent from each sensor to control the ABS, EBD, BA, TRC and VSC.

    • Sends and receives control signals to or from the ECM, yaw rate sensor, steering angle sensor, etc. via CAN communication.
    Brake actuator assembly

    • Consists of the master cylinder cut solenoid valves, retention solenoid valves, pressure reduction solenoid valves, pump motor and reservoir, and adjusts the brake fluid pressure applied to each wheel cylinder.

    • Houses the skid control ECU.
    Motor relay

    • Supplies power to the pump motor.

    • Housed in the skid control ECU.
    ABS solenoid relay

    • Supplies power to each solenoid.

    • Housed in the skid control ECU.
    ABS warning light

    • Comes on to inform the driver that a malfunction in the ABS and/or BA has occurred.

    • Blinks to output ABS DTCs.
    Brake warning light

    • Comes on to inform the driver that the amount of brake fluid is low.

    • Comes on to inform the driver that the parking brake is applied.

    • Comes on to inform the driver that a malfunction in the EBD has occurred.
    Slip indicator light

    • Comes on to inform the driver that a malfunction in the VSC and/or TRC has occurred.

    • Blinks to inform the driver that TRC and/or VSC are operating.

    • Blinks to output VSC DTCs.
    VSC OFF indicator light Illuminates to inform the driver when VSC OFF mode is selected.
    TRC OFF indicator (multi-information display) Displays to inform the driver that TRC OFF mode is entered using the VSC OFF switch.
    ECM Controls the engine output when TRC and/or VSC is operating with the skid control ECU via CAN communication.
    VSC OFF switch Pressing this switch turns off traction control, and pressing and holding this switch turns off traction control and VSC.
    Stop light control relay The stop light control relay is built into the stop light switch assembly.
    Main body ECU (instrument panel junction block assembly) Transmits the parking brake switch signal to the skid control ECU.
    Parking brake switch assembly Detects the parking brake pedal status.
    Brake fluid level warning switch (brake master cylinder reservoir sub-assembly) Detects the brake fluid level.
    Power steering ECU assembly Operates cooperatively with the skid control ECU to control the steering assist torque.