CHASSIS - BRAKE
255CH131
Skid Control
ECU
The fluid pressure
is increased by the
brake actuator
Master Cylinder
Pressure Sensor
Signal
Brake Pedal
Stroke Sensor
Signal
with Brake Assist Function
without Brake Assist Function
282CH115
170CH18
Braking
Force
with Brake
Assist Function
without Brake
Assist Function
Time
CH-35
Outline of Brake Assist Function
The brake assist function interprets a quick push of the brake pedal as emergency braking and supplements
the braking power applied if the driver has not stepped hard enough on the brake pedal. In emergencies,
drivers, especially inexperienced ones, often panic and do not apply sufficient pressure on the brake pedal.
Based on the signals from the master cylinder pressure sensors and the brake pedal stroke sensor, the skid
control ECU calculates the speed and the amount of the brake pedal application and then determines the
intention of the driver to make an emergency braking. If the skid control ECU determines that the driver
intends emergency braking, the function activates the brake actuator to increase the brake fluid pressure.
The brake assist function in combination with ABS helps ensure the vehicle’s brake performance.
A key feature of Brake Assist function is that the timing and the degree of braking assistance are designed
to ensure that the driver does not discern anything unusual about the braking operation. When the driver
intentionally eases up on the brake pedal, the function reduces the amount of assistance it provides.
: There is no difference of the maximum brake performance between the vehicles with and without brake
assist function.