Hba (Hydraulic Brake Assist System) - SSANGYONG 2004 Rexton 2.7XDi Workshop Manual

8E2-16

HBA (Hydraulic Brake Assist System)

(1) Purpose
HBA (Hydraulic Brake Assist) system helps in an emergency braking situation when the driver applies the brake fast, but not with
sufficient pressure, which leads to dangerously long braking distance. ECU recognizes the attempt at full braking and transmits the
signal calling for full brake pressure from the hydraulic booster. An inexperienced, elderly or physically weak driver may suffer from the
accident by not fully pressing the brake pedal when hard braking is required under emergency. The HBA System increases the
braking force under urgent situations to enhance the inputted braking force from the driver.
Based on the fact that some drivers depress the brake pedal too soft even under when hard braking is necessary, the
HECU system is a safety supplementary system that builds high braking force during initial braking according to
pressure value of the brake pressure sensor and the pressure changes of the pressure sensor intervals.
When the system is designed to apply high braking force when brake pedal is depressed softly by an elderly or
physically weak driver, the vehicle will make abrupt stopping under normal braking situation due to high braking pressure
at each wheels.
(2) Operation
The brake pressure value and the changed value of the pressure sensor are the conditions in which the HBA System
operates. There are 2 pressure sensors under the master cylinder. When the ESP ECU system determines that emer-
gency braking is present, the pump operates, the brake fluid in the master cylinder is sent to the pump and the braking
pressure is delivered to the wheels via the inlet valves.
If the drive depress the brake pedal slowly, the pressure change is not high. In this case, only the conventional brake
system with booster is activated.
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
Experienced drivers
Inexperienced drivers
Elderly and physically
weak drivers
Time (s)
Y220_8E2018
Y220_8E2019
ESP SYSTEM
REXTON SM - 2004.4