System Description

FUNCTION DESCRIPTION
1. VDIM (Vehicle Dynamics Integrated Management)
  1. VDIM integrally controls engine output and braking in coordination with steering control to ensure vehicle running, cornering and stopping performance for active safety.
2. Steering Cooperation Control
  1. Effects cooperative control with the power steering ECU in order to provide steering assist in accordance with the operating conditions of the vehicle.
3. 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.
4. EBD (Electronic Brake force Distribution)
  1. The 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 the right and left wheels, helping maintain vehicle behavior.
5. BA (Brake Assist)
  1. The primary purpose of the brake assist is to provide auxiliary brake force to assist a driver who cannot generate a large brake force during emergency braking, thus helping ensure the vehicle's brake performance.
6. TR(A)C (Traction Control)
  1. The TR(A)C 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.
7. VSC (Vehicle Stability Control)
  1. The VSC helps restraint sideways slippage of the vehicle during a strong front skid or strong rear wheel skid, such as may occur while cornering.
8. Hill-start Assist Control (for Automatic Transmission)
  1. The hill-start assist control generates four-wheel hydraulic pressure when the brake pedal is further depressed while is stationary. This pressure is generated in order to prevent the vehicle from moving backward.

FUNCTION OF COMPONENTS

Component	Function
Skid control ECU	Processes signals sent from each sensor to control the ABS, BA, TR(A)C, and VSC. Sends and receives control signals to or from the ECM, yaw rate and acceleration sensor, and steering angle sensor, etc. via CAN communication.
Brake actuator assembly	Consists of the master cylinder cut solenoid valve, retention solenoid valves, pressure reduction solenoid valves, pump motor, and reservoir, and adjusts the brake fluid pressure applied to each wheel cylinder.
ABS solenoid relay	Supplies power to each solenoid.
ABS motor relay	Supplies power to the pump motor.
ABS motor fail safe relay	Cuts off power to the motor when the pump motor circuit malfunctions.
Stop light control (BRK-LP) relay*1	Turns on the stop lights hill-start assist control operation.
Speed sensor	Detects the wheel speed and sends the signal to the skid control ECU.
Steering angle sensor	Detects the steering amount and direction and sends the signals to the skid control ECU via CAN communication. Has a magnetic resistance element which detects the rotation of the magnet housed in the detection gear in order to detect the changes in steering amount and direction through magnetic resistance.
Yaw rate and acceleration sensor	Acceleration sensor measures the capacity of the condenser that changes the distance between the electrodes depending on G force, which occurs when the vehicle is accelerated, and converts the measured value into electrical signals. Yaw rate sensor detects the vehicle's angular velocity (yaw rate) in the vertical direction based on the amount and direction of the piezoelectric ceramics deflection.
Master cylinder pressure sensor	Detects the fluid pressure in the master cylinder.
Stop light switch	Detects the brake operating conditions and inputs the results to the skid control ECU.
Brake pedal load sensing switch	Turned on when the brake pedal is depressed.
Parking brake switch	Detects the parking brake operating conditions and inputs the signals to the skid control ECU.
VSC OFF switch	Pressing this switch turns off TR(A)C and pressing and holding this switch turns off TR(A)C and VSC.
ECM	Controls the engine output when TR(A)C and/or VSC are operating with the skid control ECU via CAN communication.
Skid control buzzer	Intermittently sounds to inform the driver that the VSC is operating.
ABS warning light	Comes on to inform the driver that a malfunction in the ABS and/or BA has occurred. Blinks to output DTCs.
Brake warning light	Comes on to inform the driver that the parking brake is ON when the system is normal, the brake fluid has decreased, or the master cylinder pressure is lost as the brake pedal load sensing switch is pressed. Comes on to inform the driver that a malfunction in the EBD has occurred.
VSC OFF indicator light	Comes on to inform the driver when the VSC off mode is entered using the VSC OFF switch.
Slip indicator light	Blinks to inform the driver that TR(A)C and VSC are operating. Blinks to output DTCs.
Master caution indicator light	Comes on to inform the driver that a malfunction in the brake control system has occurred.
Multi-information display (TR(A)C OFF indicator)	Displays to inform the driver when the TR(A)C off mode is entered using the VSC OFF switch. Comes on to alert the driver when the skid control ECU detects a malfunction in the TR(A)C, VSC and/or hill-start assist control.

*1: for automatic transmission