VEHICLE STABILITY CONTROL SYSTEM SYSTEM DESCRIPTION


  1. FUNCTION DESCRIPTION


    1. Anti-lock Brake System (ABS)


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

    2. Electronic Brake Force Distribution (EBD)


      1. The EBD utilizes ABS, achieving proper brake force distribution between the front and rear wheels in accordance with the driving conditions. In addition, during braking while cornering, the EBD also controls the brake forces of the right and left wheels, helping maintain vehicle stability.

    3. Brake Assist (BA)


      1. The primary purpose of brake assist is to provide an auxiliary brake force to assist a driver who cannot generate a large brake force during emergency braking, thus helping ensure the vehicle's braking performance.

      2. If the brake booster malfunctions and the skid control ECU judges that the brake pedal force applied by the driver is not sufficient to ensure adequate braking force, brake assist is used to enhance the braking force.

    4. Traction Control (TRC)


      1. The TRC helps restrain the slippage of the drive wheels if the driver depresses the accelerator pedal excessively when starting off or while accelerating on a slippery surface.

    5. Vehicle Stability Control (VSC)


      1. The VSC helps restrain sideways slippage of the vehicle during a strong front wheel skid or strong rear wheel skid, which may occur while cornering.

    6. VSC (Cooperative Control with EPS) / VSC+


      1. This performs cooperative control with the power steering ECU assembly, front steering control ECU (w/ VGRS system) and rear steering control ECU (w/ DRS system) in order to provide steering assist in accordance with the operating conditions of the vehicle.

    7. Hill-start Assist Control


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

    8. Emergency Brake Signal


      1. In the case of emergency braking, the emergency brake signal flashes the stop lights to alert the drivers in following vehicle (w/ Emergency Brake Signal).

  2. FUNCTION OF COMPONENTS

    Component Function
    Brake Actuator Assembly Skid Control ECU

    • Judges the vehicle driving condition based on the signals from each sensor, and sends the brake control signals to the brake actuator.

    • Based on signals from various sensors, outputs the emergency brake signal control signals.
    Master Cylinder Pressure Sensor Assembled in the brake actuator assembly, detects the master cylinder pressure.
    Pump Motor Drives the pumps inside the brake actuator assembly.
    Solenoid Valves Change the fluid path based on the signals from the skid control ECU during the operation of the brake control system functions in order to control the fluid pressure applied to each wheel cylinder.
    Skid Control ECU ABS Motor Relay Supplies power to the pump motor.
    ABS Solenoid Relay Supplies power to the solenoid valves.
    Speed Sensors Detect the wheel speed of each of the 4 wheels.
    Combination Switch Assembly VSC OFF Switch Enables the driver to select the Normal mode, TRC off mode, or VSC off mode.
    Air Conditioning Control Assembly Hazard Warning Signal Switch Transmits a hazard warning light on/off request signal to the skid control ECU.
    Stop Light Switch Assembly Detects when the brake pedal is depressed.
    Main Body ECU (Multiplex Network Body ECU) Transmits the parking brake switch signal to the skid control ECU.
    Parking Brake Switch Assembly Detects the parking brake pedal status.
    ECM

    • Sends the throttle position signal, accelerator pedal position signal, engine speed signal etc., to the skid control ECU.

    • Controls the engine output based on the signals received from the skid control ECU.
    Yaw Rate and Acceleration Sensor

    • Detects the vehicle's longitudinal and lateral acceleration.

    • Detects the vehicle's yaw rate.
    Steering Angle Sensor Detects the direction and angle of the steering wheel.
    Combination Meter Assembly ABS Warning Light Illuminates to alert the driver when the skid control ECU detects a malfunction in the ABS.
    Brake Warning Light

    • Illuminates to alert the driver when the skid control ECU detects a malfunction in the EBD.

    • Illuminates to alert the driver when the brake fluid level is low.
    VSC OFF Indicator Light Illuminates to inform the driver when VSC off mode is selected.
    Slip Indicator Light

    • Blinks to inform the driver when the TRC and VSC are operational.

    • Illuminates to alert the driver when the skid control ECU detects a malfunction in the TRC or VSC.
    Multi-information Display

    • Displays an information message when TRC OFF mode is selected.

    • Displays a warning message when the skid control ECU detects a malfunction in the ABS or EBD.
    Brake Master Cylinder Reservoir Assembly Brake Fluid Level Warning Switch Detects the brake fluid level.
    Brake Pedal Support Assembly Brake Pedal Load Sensing Switch Detects the brake pedal load.
    Semiconductor PWR Integration ECU Illuminates or flashes the stop lights in accordance with the signals from the stop light switch assembly and skid control ECU.
    Power Steering ECU Assembly Controls the steering assist torque based on the signals received from the skid control ECU.
    Front Steering Control ECU*1 Controls the turning angle of the front wheels based on the signals received from the skid control ECU.
    Rear Steering Control ECU*2 Controls the turning angle of the rear wheels based on the signals received from the front steering control ECU.

    *1: w/ VGRS System

    *2: w/ DRS System