2006 SSANGYONG RODIUS ECU

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ESP SYSTEM
RODIUS 2007.07
4892-01
(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 emergency 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.

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RODIUS 2007.07
4892-01
ESP SYSTEM
▶When applied ABS (decreased pressure)
The pressure decreases just before the wheel speed drops and the wheels. The inlet valve
closes and the outlet valve opens as in the ABS HECU and the oil is gathered at the low
pressure chamber while no additional oil is being supplied.
Then the pump operates to allow fast oil drainage.

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ESP SYSTEM
RODIUS 2007.07
4892-01
▶Hydraulic Diagram of HBA
The above figure shows one front and one rear wheel and the same hydraulic circuit forms as
in the ESP operation.
When HECU recognizes that it is an emergency and it is required for hard braking, depending
on the pressure value of the brake pressure sensor and pressure changes caused by the
pressure sensor timing, it operates the pump immediately to apply the brake pressure at the
wheels.
Then, the pressure in the pump increases until just before the corresponding wheel gets locked.
The motor still keeps rotating and the outlet valve and the separation valve are will stay closed.
When the wheel starts to lock, the HBA function cancels and switches to ABS operation.

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RODIUS 2007.07
4892-01
ABS SYSTEM
3. ON-VEHICLE SERVICE
(1) Electronic system service precautions
Take care to avoid electronic brake control module (HECU) circuit overloading. In testing for
opens or shorts, do not ground or apply voltage to any circuit unless instructed to do so by the
diagnostic procedure. Test circuits only with a high-impedance multi-meter. Never remove o
r
apply power to any control module with the ignition switch in the ON position. Always turn the
ignition to the OFF position before removing or connecting battery cables, fuses or connectors.
(2) General service precautions
Disconnect the HECU connector before performing any vehicle welding work using an electric
arc welder. Do not attempt to disassemble any component designated as nonserviceable. The
hydraulic modulator and the HECU can be seperated. (There is however no access to repai
r
the each components.)
(3) Bleeding system
Replacement modulators are shipped already filled and bled. In normal procedures requiring
removal of the modulator, such as to replace the HECU, air will not enter the modulator, and
normal bleeding will be all that is needed.
If air enters the hydraulic modulator, or if an unfilled modulator is installed, use the brake
bleeding program in the scan tool to bleed the modulator. Manual bleeding of the hydraulic
modulator is not possible.
1) Service Precautions
Brake Fluid may irritate eyes and skin. In case of contact, take the following actions:
Eye contact - rinse thoroughly with water.
Skin contact - wash with soap and water.
Ingestion - consult a physician immediately. -
-
-
To help avoid personal injury due to poor braking. DO NOT Tap into the vehicle’s
brake system to operate a trailer brake system.
When fasteners are removed, always reinstall them at the same location from which they
were removed. If a fastener needs to be replaced, use the correct part number fastener
for is not available, a fastener of equal size and strength (or stronger) may be used.
Fasteners that are not reused, and those requiring thread-locking compound will be
called out. The correct torque values must be used when installing fasteners that require
them. If the above procedures are not followed, parts or system damage could result.

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RODIUS 2007.07
4892-01
ABS SYSTEM
1. COMPONENTS AND LOCATION
Newly introduced ABS has a different shape of integrated hydraulic modulator and HECU
(Hydraulic and Electronic Control Unit) compared to existing ABS. And, the wheel speed senso
r
uses different method to detect wheel speed. The basic function of the ABS that maintains the
vehicle stability by controlling the steerability of the vehicle when braking has not been
changed.

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RODIUS 2007.07
4892-01
ABS SYSTEM
Pressure Decreases in the Circuit when ABS is Operating ▶
Pressure Increases in the Circuit when ABS is Operating ▶
Even when the hydraulic pressure on each circuit is stable, the wheel can be locked as the
wheel speed decreases. This is when the ABS ECU detects the wheel speed and the vehicle
speed and gives the optimized braking without locking the wheels. In order to prevent from
hydraulic pressure increases, the inlet valve is closed and the outlet valve is opened. Also, the
oil is sent to the low pressure changer and the wheel speed increases again. The ABS ECU
operates the pump to circulate the oil in the low pressure chamber to the master cylinder. This
may make the driver to feel the brake pedal vibration and some noises.
As the wheel speed increases, the inlet valve opens and the wheel’s pressure increases
due to the master cylinder pressure. The oil in the low pressure chamber circulates to the wheel
by the pump and the wheel speed decreases as the hydraulic pressure at wheel increases. This
operation continues repetitively until there are no signs that the ECU is locking the wheels.
When the ABS hydraulic pressure control takes place, there may be some vibration and noises
at the brake pedal.

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ABS SYSTEM
RODIUS 2007.07
4892-01
(3) COMPONENTS DESCRIPTION
HECU (Hydraulic & Electronic Control Unit) ▶
Motor Pump ▶
Valve Body ▶
HECU consists of motor pump (1), solenoid
valve (2) and ECU (3).
ECU connector has 47 pins and the numbe
r
of valves in valve body is 6 when equipped
with only ABS and 12 when equipped with
ESP system.
The motor is operated when ABS is
activated. The cam-shaped output shaft o
f
the motor enables the brake system to
receive and supply the brake fluid during the
motor operation.
The cam bushing is installed between
plungers and it draws and discharges the
brake fluid.

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RODIUS 2007.07
4892-01
ABS SYSTEM
Pumping
▶
ECU (Including Solenoid Valves ? ESP Equipped Model)
▶
ECU lower cover)
▶
When the cam pushes the left plunger
during motor operation, the system pressure
is generated in the left cylinder. At this time,
the right plunger is expanded by spring force
and the expanded volume of the right
cylinder draws the brake fluid.
HECU controls the hydraulic valves by
supplying or cutting off the voltage to
solenoid valves depending on the wheel
speed and other information from wheel
speed sensors.
The figure shown in left side is for ESP
ECU. There are two channels for front
wheels and one channel for rear wheels.
Each channel has one inlet and one outlet
valve, therefore,
there are six solenoid valves.
The electrical components are weak to
moisture. To protect ECU, GoreTex-based
plate is used at ECU lower cover. The vent
hall (arrow) allows air to ventilate but does
not allow moisture to penetrate.