System Description

HINT:

• The skid control ECU is located within the ABS & TRACTION actuator assembly.

• The yaw rate sensor and acceleration sensor are combined and in a signal unit. This unit communicates with the skid control ECU through CAN communication.

(a) ABS (Anti-lock Brake System)

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

ABS & TRACTION Actuator Assembly

Each Speed Sensor

Skid Control ECU

Pump Motor

■i

Gateway ECU

Solenoid Valve

Each Wheel Cylinder

Combination Meter

CAN Communication System

Multiplex Communication System (Bean Bus)

Hydraulic Pressure

ABS Warning Light

C129995E02

(1) Operation description

The skid control ECU detects wheel lock condition by receiving vehicle speed signals from each speed sensor, and sends control signals to the pump motor and solenoid valve. The pump motor and solenoid valve avoid wheel lock by controlling the hydraulic pressure of each wheel cylinder.

The ABS warning light comes on when the ABS system is malfunctioning.

(b) EBD (Electronic Brake force Distribution)

The EBD control utilizes ABS, realizing proper brake force distribution between the front and rear wheels in accordance with driving conditions. In addition, when braking while cornering, it also controls the brake forces of the right and left wheels, helping to maintain vehicle behavior.

ABS & TRACTION Actuator Assembly

ABS & TRACTION Actuator Assembly

(1) Operation description

The skid control ECU receives the speed signal from each speed sensor to detect the slip condition of the wheels and sends the control signal to the solenoid. The solenoid valve controls the hydraulic pressure of each wheel cylinder and splits the control power properly between the front and rear wheels and the right and left wheels. Both of the ABS and BRAKE warning lights come on to indicate a malfunction in the EBD system.

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

ABS & TRACTION Actuator Assembly

Each Speed Sensor

Skid Control ECU

Pump Motor

Solenoid Valve

■i

Gateway ECU

Master Cylinder Pressure Sensor

CAN Communication System

Multiplex Communication System (Bean Bus)

Hydraulic Pressure

Each Wheel Cylinder

Combination Meter

ABS Warning Light

(1) Operation description

The skid control ECU receives the hydraulic pressure signal from the master cylinder pressure sensor to determine whether brake assist is necessary or not. If brake assist is deemed necessary, the skid control ECU sends control signals to the pump motor and solenoid. The pump and the solenoid valve then control the pressure applied to each wheel cylinder. The ABS warning light comes on to indicate a malfunction in the BA (brake assist) system.

(d) TRAC (Traction Control)

The TRAC system helps prevent the drive wheels from slipping if the driver presses down on the accelerator pedal excessively when starting off or accelerating on a slippery surface.

ABS & TRACTION Actuator Assembly

: CAN Communication System : Multiplex Communication System (Bean Bus) : Hydraulic Pressure

ABS & TRACTION Actuator Assembly

C130016E01

(1) Operation description

The skid control ECU detects vehicle's slip condition by receiving signals from each speed sensor and ECM via CAN communication. The skid control ECU controls engine torque with the ECM via CAN communication and hydraulic pressure through the pump and solenoid valve. The SLIP indicator light blinks when the system is operating.

(e) VSC (Vehicle Stability Control)

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

ABS & TRACTION Actuator Assembly

ABS & TRACTION Actuator Assembly

: Hydraulic Pressure

C130017E01

: Hydraulic Pressure

C130017E01

(1) Operation description

The skid control ECU determines vehicle condition by receiving signals from the speed sensor, yaw rate and acceleration sensor and steering angle sensor. The skid control ECU controls engine torque with the ECM via CAN communication, and hydraulic pressure with the pump and solenoid valve. The SLIP indicator light blinks and the buzzer sounds when the system is operating.

2. ABS with EBD & BA & TRAC & VSC OPERATION (a) The skid control ECU calculates vehicle stability tendency based on the signals from the speed sensor, yaw rate and acceleration sensor and steering angle sensor. In addition, it evaluates the results of the calculations to determine whether any control actions (control of the engine output torque by electronic throttle control and the wheel brake pressure by the ABS & TRACTION actuator assembly ) should be implemented.

(b) The SLIP indicator blinks and the skid control buzzer sounds to inform the driver that the VSC system is operating. The SLIP indicator also blinks when traction control is operating, and the operation being performed is displayed.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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