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. EBD control utilizes the 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 stability.

    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 to utilize the vehicle's braking performance.

    4. Traction Control (TRC)

      1. The TRC system 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. The VSC system helps restrain sideways slippage of the vehicle during a strong understeer tendency or strong oversteer tendency while cornering.

    6. Hill-start Assist Control

      1. When starting uphill, this control maintains the brake hydraulic pressure to all 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 switch, 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, 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.

    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.

    Stop Light Switch Assembly

    Detects the brake pedal depressing signal.

    Back-up Light Switch Assembly*

    Detects the status of the reverse gear, and inputs it to the skid control ECU.

    Parking Brake Switch Assembly

    Detects when the parking brake lever is pulled up.

    VSC OFF Switch

    Enables the driver to select the Normal mode, TRC off Mode, or VSC off mode.

    ECM

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

    • Based on the signals from the skid control ECU, controls the engine output.

    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 deceleration.

    • 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 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.

    • Illuminates to alert the driver when the brake booster has a malfunction.

    TRC OFF Indicator Light

    Illuminates to inform the driver of TRC off mode or VSC off mode being selected.

    VSC OFF Indicator Light

    Illuminates to inform the driver of VSC off mode being selected.

    Slip Indicator Light

    • Blinks to inform the driver when the TRC or VSC operates.

    • Illuminates to alert the driver if the TRC or VSC system malfunctions.

    Brake Master Cylinder Reservoir Assembly

    Brake Fluid Level Warning Switch

    Detects the brake fluid level.

    Hazard Warning Signal Switch Assembly

    Transmits a hazard warning light on/off request signal to the skid control ECU.

*: for Manual Transaxle