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System Description [06/2016 - ]

  1. FUNCTION DESCRIPTION 
    1. Anti-lock Brake System (ABS)
      1. 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. EBD control utilizes ABS, realizing proper brake force distribution between the front and rear wheels in accordance with the driving conditions. In addition, during braking while cornering, it also controls the brake forces of the right and left wheels, helping maintain vehicle behavior.
    3. Brake Assist (BA)
      1. The primary purpose of brake assist is to provide supplementary brake force to assist a driver who cannot generate a large brake force during emergency braking, thus helping ensure the vehicle's braking performance.
    4. Traction Control (TR(A)C)
      1. Helps restrain the slippage of the drive wheels if the driver depresses the accelerator pedal excessively when starting off or accelerating on a slippery surface.
    5. Vehicle Stability Control (VSC)
      1. Helps restrain sideways slippage of the vehicle during a strong understeer tendency or strong oversteer tendency while cornering.
    6. Limited Slip Differential Control (LSD)
      1. The LSD function detects a difference in rotation speeds between the left and right drive wheels. If there is a difference in rotation speeds between them, this function applies brake to the drive wheel that rotates faster than the other using pressurization function of the VSC* to minimize the difference.
      2. The function makes it possible to start and accelerate the vehicle stably.

        * : This function always activates regardless of ON/OFF of the VSC mode.

    7. Hill-start Assist Control (HAC)
      1. When the vehicle starts off on a steep hill, hill-start assist control detects the backward descent of the vehicle and performs 4-wheel hydraulic pressure control to reduce the speed of the vehicle.

        HINT: 

        The system does not operate when the shift lever is in P or N, or when the vehicle is running/rolling back up a slope with the shift lever in R.

  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 switch, and sends the brake control signals to the brake actuator assembly.
    Master Cylinder Pressure Sensor 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, 2 reservoir 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.
    Yaw Rate and Acceleration Sensor
    • The yaw rate sensor detects the vehicle's yaw rate.
    • The acceleration sensor detects the vehicle's longitudinal and lateral acceleration.
    Skid Control ECU ABS Motor Relay Supplies power to the pump motor.
    ABS Solenoid Relay Supplies power to the solenoid valves.
    Speed Sensor Detect the wheel speed of each of the 4 wheels.
    Pattern Select Switch Assembly VSC OFF Switch Enables the driver to select normal mode, TR(A)C OFF mode or VSC OFF mode.
    TRACK Switch Enables the driver to select normal mode or TRACK mode.
    Stop Light Switch Assembly Detects the brake pedal depressing signal.
    Main Body ECU (Network Gateway 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 accelerator pedal position signal, engine speed signal etc., to the skid control ECU.
    • Based on the signals from the skid control ECU, controls the engine output.
    TCM* Sends the gear position signal to the skid control ECU.
    Steering 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.
    TR(A)C OFF Indicator Light Illuminates to inform the driver when TR(A)C OFF mode is selected.
    VSC OFF Indicator Light Illuminates to inform the driver when VSC OFF mode or TRACK mode is selected.
    TRACK Indicator Light Illuminates to inform the driver when TRACK mode is selected.
    Slip Indicator Light
    • Blinks to inform the driver when the TR(A)C or VSC is performing control.
    • Illuminates to alert the driver when the skid control ECU detects a malfunction in the TR(A)C and/or VSC.
    Hill Start Assist Indicator Allows the driver to turn hill-start assist control on and off.

    *: for Automatic Transmission

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