System Description [09/2014 - 10/2015]

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2020 Lexus GS 350, 2019 Lexus GS 350, 2018 Lexus GS 350, 2017 Lexus GS 350, and 2017 Lexus GS 200t. However, it is still accessible from the selected car via links, so may be relevant.

FUNCTION DESCRIPTION
1. Vehicle Dynamics Integrated Management (VDIM)
  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. Performs cooperative control with the power steering ECU in order to provide steering torque assist in accordance with present vehicle dynamics.
3. Anti-lock Brake System (ABS)
  1. ABS helps prevent the wheels from locking when the brakes are applied firmly or when braking on a slippery surface.
4. 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, when braking while cornering, it also controls the brake forces applied to the right and left wheels, helping to stabilize vehicle behavior.
5. 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.
6. Traction Control (TRAC)
  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.
7. Vehicle Stability Control (VSC)
  1. Helps restrain sideways slippage of the vehicle during a strong understeer tendency or strong oversteer tendency while cornering.
8. Hill-start Assist Control
  1. When the vehicle starts off on a steep or a slippery hill, Hill-start Assist Control performs 4-wheel hydraulic pressure control to prevent the vehicle from moving backward.

FUNCTION OF COMPONENTS

Component		Function
Brake actuator assembly	Solenoid valve Master cylinder cut solenoid valve	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 each wheel cylinder.
	Master cylinder pressure sensor	Installed in the brake actuator, detects the master cylinder pressure.
	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.
	Motor relay	Supplies power to the pump motor.
	Solenoid relay	Supplies power to the solenoid valves.
Combination meter	Brake system warning light (red indicator)	Illuminates together with the ABS warning light to alert the driver when the skid control ECU detects a malfunction in the EBD control. Illuminates to alert the driver when the skid control ECU detects a malfunction in the brake booster. Illuminates to alert the driver when the brake fluid level is low.
	ABS warning light	Illuminates to alert the driver when the skid control ECU detects a malfunction in the ABS.
	Slip indicator light	Blinks to inform the driver when TRAC, VSC or hill-start assist control is operating. Illuminates to alert the driver when the skid control ECU detects a malfunction in the TRAC, VSC or hill-start assist control.
	VSC OFF indicator light	Illuminates to inform the driver when VSC OFF mode is selected.
	Master warning light	Illuminates to alert the driver when the skid control ECU detects a malfunction in the brake control system.
	Multi-information display	Displays a warning message to alert the driver when TRAC OFF mode is selected. Displays a warning message to alert the driver when the skid control ECU detects a malfunction in the brake control function.
	Meter buzzer	Emits a warning sound to inform the driver when hill-start assist control operation is started or finished.
No. 2 integration relay		Illuminates the stop lights while hill-start assist control is operating.
Steering sensor		Detects the direction and angle of the steering wheel.
Yaw rate sensor		Detects the vehicle's longitudinal and lateral acceleration and deceleration. Detects the vehicle's yaw rate.
Speed sensor		Detect the wheel speed of each of the 4 wheels.
Stop light switch		Detects brake pedal operation.
Brake pedal load sensing switch		Detects the brake pedal depression force.
VSC OFF switch		Enables the driver to select Normal mode, TRAC OFF mode, or VSC OFF mode.
ECM		Sends the throttle position signal, accelerator pedal position signal, engine speed signal, etc. to the skid control ECU. Based on the signals received from the skid control ECU, controls the engine output.