2012 SSANGYONG NEW ACTYON SPORTS lock

09-4
2. SYSTEM OVERVIEW
1) Terms and Definition
CBS: Conventional Brake System
ABS: Anti-Lock Brake System
EBD: Electronic brake-Force Distribution
ESP: Electronic Stability Program
ABD: Automatic Braking Differential
ASR: Acceleration Slip Regulation
AYC: Active Yaw Control (Understeer and Oversteer Control)
HBA: Hydraulic Brake Assistant
ARP: Active Rollover Protection
HSA: Hill Start Assistant
Brake pad: Brake pad is a component of disk brakes used in automotive and other
applications. Brake pad is steel backing plates with friction material bound to the surface that
faces the brake disc.
Brake disc: The brake disc is a device for slowing or stopping the rotation of a wheel while it is
in motion.
Brake caliper: To stop the wheel, friction material in the form of brake pads (mounted on a
device called a brake caliper) is forced hydraulically against both sides of the disc. Friction
causes the disc and attached wheel to slow or stop.
Brake master cylinder: The brake master cylinder is a control device that converts non-
hydraulic pressure (commonly from a driver's foot) into hydraulic pressure, in order to move
other device(s) which are located at the other end of the hydraulic system, such as one or
more slave cylinders. As piston(s) move along the bore of the master cylinder, this movement
is transferred through the hydraulic fluid, to result in a movement of the slave cylinder(s). The
hydraulic pressure created by moving a piston (inside the bore of the master cylinder) toward
the slave cylinder(s) compresses the fluid evenly, but by varying the comparative surface-area
of the master cylinder and/or each slave cylinder, one will vary the amount of force and
displacement applied to each slave cylinder (relative to the amount of force and displacement
that was applied to the master cylinder). -
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FunctionVehicle with CBS
Vehicle with ABS/EBD Vehicle with ESP
ABS
Not appliedApplied
Applied EBD Applied
ABD
Not applied ASR
AYC
HBA
ARP
2) Functions

09-14
Specified value (B)155mm
Push rod
Stop lamp
switch Pedal Height ▶
Check the pedal height with below
procedures: -
Start the engine and measure the length
(A) between floor mat and pedal.
If the measured value is out of the
specified value, adjust the length. 1.
2.
Adjust the pedal height with below
procedures: -
Disconnect the stop lamp switch connector.
Unscrew the lock nut and remove the stop
lamp switch assembly.
Loosen the lock nut on the pedal push rod.
Turn the pedal push rod to adjust the pedal
height.
Tighten the lock nut.
Install the stop lamp switch assembly.
Connect the stop lamp switch connector.
Check if the stop lamps come on when
pressing the brake pedal around 5 mm.
If the stop lamp dpes not come on, adjust
the stop lamp switch assembly again.
If the stop lamps come on, tighten the lock
nut and measure the pedal height again. 1.
2.
3.
4.
5.
6.
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9.
10.

09-174850-01
Brake Fluid ▶
Brake Fluid Type ▶ 1. Color
Ligh gold (New oil) → Brown → Black -
2. Service Interval/Type
Change: every 2 years, Type: DOT4
The water in the brake fluid has an adverse effect to the brake system. If the fluid contains
around 3% of water, the boiling point of the brake fluid goes down by 25%. It will cause
the vapor lock frequently.
Water content in fluid: around 3% after 18 months, around 7~10% after few years
The water ib fluid makes the corrosion in the brake lines, deforms and deteriorates the
rubber components, brake calipers and pistons. -
DOT4: Brake fluid for premium vehicle. Lower water absorbing rate AND higher boiling point
than DOT3
Brake Fluid Level Check ▶
The brake fluid level should be between "MAX"
and "MIN" on the reservoir. If it is below "MIN"
mark, check for oil leaks and refill the reservoir
with the specified fluid.

10-34892-01
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←

10-6
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

10-134892-01
5. SYSTEM OPERATION
1) Block Diagram of ABS HECU

10-14
2) Basic Theory of ABS Function
To give you a better understanding of the tasks and functions of ABS, we will first look at the
physics principles.
(1) Stopping distance
(2) Brake force on a wheel
The maximum possible brake force on a wheel depends on the wheel load and the adhesion
coefficient between tire and carriageway. With a low adhesion coefficient the brake force, which
can be obtained is very low. You are bound to know the result already from driving on winter
roads. With a high adhesion coefficient on a dry road, the brake force, which can be obtained, is
considerably higher. The brake force, which can be obtained, can be calculated from below
formula:
Maximum brake force ▶
FBmax = wheel load FR x coefficient of
frictionMh
The braking process cannot be described
sufficiently accurately with the brake forces
calculated. The values calculated only apply if
the wheel is not locked. In the case of a
locking wheel, the static friction turns into
lower sliding friction, with the result that the
stopping distance is increased. This loss of
friction is termed "slip" in specialist literature.
The stopping distance depends on the vehicle weight and initial speed when braking starts. This
also applies for vehicle with ABS, where ABS always tries to set an optimum brake force on each
wheel. As great forces are exerted between the tires and the carriageway when braking, even with
ABS the wheels may scream and rubber is left on the road. With an ABS skid mark one may be
able to clearly recognize the tire profile. The skid mark of an ABS vehicle does not however leave
any hint of the speed of the vehicle in the case of an accident, as it can only be clearly drawn at
the start of braking.

10-154892-01
Slip ▶
The brake slip is the difference between the vehicle speed and the wheel circumference speed. If
the wheel locks, the slip is greatest, that is 100 %. If the wheel is running freely and un-braked,
the slip is the lowest, equal to 0 %. Slip can be calculated from the vehicle speed Vveh and the
wheel speed Vw. The equation for this is:
Vveh = 100 km/h, Vw = 70 km/h
Slip ratio (S) = X 100%
S = 30%Vveh - Vw
Vveh
Typical Slip Curves ▶
For the various road conditions, the friction
coefficients were plotted. The typical course
of the curves is always the same. The only
special feature is shown by the curve for
freshly fallen snow, for this curve increases
at 100 % slip. In a vehicle without ABS, the
wheel locks on braking and therefore
pushes a wedge before it. This wedge of
loose surface or freshly fallen snow means
and increased resistance and as a result the
stopping distance is shorter. This reduction
in stopping distance is not possible with a
vehicle with ABS, as the wheel does not
lock. On these surfaces the stopping
distance with ABS is longer than without
ABS. The reason for this is based in physics
and not in the Anti-Lock System.
However, as mentioned before, ABS is not
about the stopping distance, but
maneuverability and driving stability, for the
vehicle with locking wheels without ABS
cannot be steered. Ex)