VEHICLE STABILITY CONTROL SYSTEM SYSTEM DESCRIPTION


  1. FUNCTION DESCRIPTION


    1. ABS (Anti-lock Brake System)


      1. 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)


      1. 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 stability.

    3. BA (Brake Assist)


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

    4. TRC (Traction Control)


      1. 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)


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

    6. Hill-start Assist Control


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

    7. Emergency Brake Signal


      1. In the case of emergency braking, the emergency brake signal flashes the hazard warning lights to alert the drivers in following vehicles.

  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 assembly.
    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

    • The hydraulic circuit has 2 master cylinder cut solenoid valves, 4 pressure holding solenoid valves and 4 pressure reduction 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 the wheel cylinders.
    Skid Control ECU Motor Relay Supplies power to the pump motor.
    Solenoid Relay Supplies power to the solenoid valves.
    Speed Sensor Detects the wheel speed of each of the 4 wheels.
    VSC OFF Switch Switches off the TRC and VSC operation.
    Stop Light Switch Assembly Detects the brake pedal depressing signal.
    ECM

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

    • Controls the engine output based on the signals received from the skid control ECU.
    Parking Brake Switch Assembly Detects when the parking brake lever is pulled up.
    Back-up Light Switch Assembly*1 Detects the R position signal of the shift lever.
    Park/neutral Position Switch Assembly*2 Detects the position signal of the shift lever.
    Airbag Sensor Assembly Yaw Rate and Acceleration Sensor

    • The airbag sensor assembly incorporates the yaw rate sensor and acceleration sensor.

    • The yaw rate sensor detects the vehicle's yaw rate.

    • The acceleration sensor detects the vehicle's longitudinal and lateral acceleration.

    • The airbag sensor assembly sends the detection signals from the yaw rate sensor and acceleration sensor to the skid control ECU via CAN communication.
    Spiral with Sensor Cable Sub-assembly Steering Angle Sensor Detects the steering 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 or brake system.

    • Illuminates to alert the driver when the brake fluid level is low.

    • Illuminates to inform the driver when the parking brake is operated.
    TRC OFF Indicator Light Illuminates to inform the driver when TRC off mode is selected.
    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 or VSC system is performing control.

    • Illuminates to alert the driver when the skid control ECU detects a malfunction in the TRC and/or VSC system.

    • *1: for Manual Transmission

    • *2: for Automatic Transmission