2012 SSANGYONG NEW ACTYON SPORTS ECU

09-32
4. HYDRAULIC CIRCUIT
Brake booster
Brake fluid reservoir and master cylinder
Front disc brake and caliper 1.
2.
3.HECU (Hydraulic & Electric Control Unit)
Rear disc brake and caliper 4.
5.

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1. SPECIFICATION
Unit DescriptionSpecification
Remark
ABS ESP
HECU Clock frequency 32MHz 50MHz
Memory 128KB 256KB
S-sensor Operating voltage 4.75~5.25V
None (functions
in sensor cluster)Installed in IP
panel behind
audio (only for
4WD) Operating temperature-30 ~ 85℃
Operating range -1.5 ~ 1.5g
Output voltage 0.5 ~ 4.5V
Wheel
speed
sensorSupplying voltage 4.5 ~ 16V←
Output current (approx. 2.7
km/h of vehicle speed)7mA(Lo) ~ 14mA
+20%←
Operating temperature-40 ~ 150℃ ←
Operating frequency 1~2500Hz←

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2. OPERATING FREQUENCY
1) Hydraulic and Electronic Control Unit (HECU)
Hydraulic and Electronic Control Unit (HECU) 1.
FL wheelRR wheelRL wheel
FR wheel
Master cylinder

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1. SYSTEM OVERVIEW
1) What is ABS?
When braking suddenly or braking on slippery roads, the vehicle keeps moving forward but the
wheels are locking and not rotating. If these happen, the vehicle may lose stability or rotate
resulting in an accident. ABS helps to maintain directional stability and control of the vehicle. ABS
is designed to secure more safety and increase the control of steering wheel during emergency
braking situation. But, ABS does not guarantee perfect safety beyond its physical limit. ABS in
this vehicle contains EBD function. In normal driving conditions, the brake system operates
without ABS function.
2) What is EBD (Electronic Brake-force Distribution)?
EBD is an automobile brake technology that automatically varies the amount of force applied to
each of a vehicle's brakes, based on road conditions, speed, loading, etc. Always coupled with
anti-lock braking systems, EBD can apply more or less braking pressure to each wheel in order to
maximize stopping power whilst maintaining vehicular control. EBD does not operate when ABS is
working.
ABS effect according to braking conditions ▶
Braking on split road Maneuvering while braking

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2) EBD (Electronic Brake-force Distribution) Warning Lamp
EBD warning lamps (brake warning lamp and ABS warning lamp) come on when the system
performs the self diagnosis and when it detects the malfunction of EBD system. However, the
brake warning lamp comes on regardless of EBD system when the parking brake is applied.
EBD warning lamp ON:
When turning the ignition switch to ON position, ABS warning lamp and the brake warning
lamp comes on for 3 seconds for self diagnosis and goes off if the system is OK
(initialization mode).
When applying the parking brake, the brake warning lamp comes on.
When the brake fluid is not sufficient, the brake warning lamp comes on.
When disengaging the connector, the warning lamp comes on.
When the system is defective, ABS warning lamp and the brake warning lamp come on
simultaneously. A.
B.
C.
D.
E.
When the solenoid valve is defective
When one or more wheel sensors are defective
When ABS HECU is defective
When the voltage is abnormal
When valve relay is defective a.
b.
c.
d.
e.
When the communication between warning lamp CAN modules in meter cluster is failed,
the warning lamp comes on. F.

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5. SYSTEM OPERATION
1) Block Diagram of ABS HECU

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2) DUMP (ABS is working) Mode
Even when the hydraulic pressure on each circuit is constant, the wheel can be locked as the
wheel speed decreases. This is when the ABS HECU detects the wheel speed and the vehicle
speed and gives the optimized braking without locking the wheels. In order to prevent the
hydraulic pressure from increasing, the inlet valve will be closed, the outlet valve will be opened
and the oil will flow into the low pressure chamber. In addition, the ABS HECU 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
Solenoid valve Valve Open/Close Pump motor
Inlet valve - Normal open (NO) valve Close
ON
Outlet valve - Normal close (NC) valve Open

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4) RISE (ABS is working) Mode
As the wheel speed increases, the inlet valve opens and the wheel's pressure increases due to
the master cylinder pressure. In addition, the pump circulates the oil in the low pressure chamber
to the wheel. As the hydraulic pressure to the wheel increases, the wheel speed will reduce. This
operation continues repetitively until there are no signs that the ABS HECU tends to lock the
wheels. Since the ABS hydraulic pressure control process takes place repeatedly for a short time,
there may be some vibration and noises at the brake pedal.
Solenoid valve Valve Open/Close Pump motor
Inlet valve - Normal open (NO) valve Open
ON
Outlet valve - Normal close (NC) valve Close