brake sensor SSANGYONG NEW ACTYON SPORTS 2012 User Guide

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Rear Wheel Speed Sensor (4WD)
Rear Brake Assembly
ABS/EBD Indicators
Parking Brake Lever
Parking Brake

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Front wheel speed sensor (4WD)
Located on the hub assembly.
Front discFront caliper assembly (2WD/4WD)
Located on the knuckle.
ABS hydraulic device and control unit
Located near the brake booster in engine compartment.

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3. ABS CONTROL LOGIC
The principal ABS control logic is the determination of the reference speed by choosing one
wheel meeting a certain condition, while sensing the speed information from 4 wheel speed
sensors when the vehicle is being driven.
For example, when the comparison of the reference speed with front right wheel speed shows a
slip, the control signal is determined according to whether it's deceleration or acceleration. If the
control conditions are met, the brake for the front right wheel will be got under control.

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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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3) Basic ABS Control
Operation of ABS control unit ▶
Applications of the ABS control unit The
signals produced by the wheel sensors are
evaluated in the electronic control unit. From
the information received, the control unit
must first compute the following variables:
Wheel speed
Reference speed
Deceleration
Slip -
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Reference speed ▶
The reference speed is the mean, I.e. average speed of all wheel speeds determined by simple
approximation.
Simplified ABS control ▶
If, during braking, one wheel speed deviates from the reference speed, the ABS control unit
attempts to correct that wheel speed by modulating the brake pressure until it again matches the
reference speed. When all four wheels tend to lock, all four wheels speeds suddenly deviate from
the previously determined reference speed. In that case, the control cycle is initiated again in
order to again correct the wheel speed by modulating the brake pressure.

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5) EBD (Electronic Brake Force Distribution) System
System description ▶
As an add-on logic to the ABS base algorithm, EBD works in a range in which the intervention
thresholds for ABS control are not reached yet.
EBD ensures that the rear wheels are sensitively monitored for slip with respect to the front axle. If
slip is detected, the inlet valves for the rear wheels are switched to pressure hold to prevent a
further increase in pressure at the rear-wheel breaks, thus electronically reproducing
a pressure-reduction function at the rear-wheel brakes.
ABS features an enhanced algorithm which includes control of the brake force distribution
between the front and rear axles. This is called Electronic Brake Distribution. In an unloading car
condition the brake efficiency is comparable to the conventional system but for a fully loaded
vehicle the efficiency of the EBD system is higher due to the better use of rear axle braking
capability.
Advantages ▶
Elimination of conventional proportioning
valve EBD utilizes the existing rear axle
wheel speed sensor to monitor rear wheel
slip.
Based on many variables in algorithm a
pressure hold, increase and/or decrease
pulsetrain may be triggered at the rear
wheels insuring vehicle stability.
Vehicle approaches the ideal brake force
distribution (front to rear).
Constant brake force distribution during
vehicle lifetime.
EBD function is monitored via ABS safety
logic (conventional proportioning valves are
not monitorable). -
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Ideal distribution
EBD start point
Cut-in point
Fixed distribution 1.
2.
3.
4.

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ESP OFF switch
Located on the left side of
instrument panel.
Rear wheel speed sensor
Located on the both ends of
rear axle.Front wheel speed sensor
Located on the hub
assembly.Sensor cluster
Located at the bottom of
center fascia panel.
Steering wheel angle sensor
Located on column shaft with
contact coil.HECU assembly
Located near the brake
booster in engine
compartment and contains
the pressure sensor.
2. COMPONENTS

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2) EBD (Electronic Brake-force Distribution) Warning Lamp (Brake
Warning Lamp)
EBD warning lamp when the system perform the self diagnosis and when it detects the
malfunction of EBD system. However, the brake warning lamp comes on regardless of EBD
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. 1.
2.
3.
4.
5.
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 module in meter cluster, the
warning lamp comes on. 6.
3) ESP OFF Indicator
ESP OFF indicator ON:
When turning the ignition switch to ON position, ESP warning lamp comes on for 3 seconds for
self diagnosis and goes off if the system is OK (initialization mode).
When the ESP OFF switch is pressed to turn off ESP function, ESP OFF indicator comes on. 1.
2.
4) ESP Warning Lamp
ESP warning lamp ON:
When turning the ignition switch to ON position, ESP warning lamp comes on for 3 seconds
for self diagnosis and goes off if the system is OK (initialization mode).
When the system is defective, the warning lamp comes on.
When the ESP function is activated, ESP warning lamp blinks with the interval of 2 Hz.
When the communication between warning lamp CAN module in meter cluster, the warning
lamp comes on. 1.
2.
3.
4.
5.
5) ESP OFF Switch
If ESP OFF switch is pressed, ESP function is deactivated and the ESP OFF indicator in the
instrument cluster comes on.
To resume the ESP function, press the switch again. At this time, ESP OFF indicator goes out.

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4) 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 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.
(3) Operating conditions
Sensor pressure: over 40 bar
Pressure changes: over 850 bar/sec
Vehicle speed: over 30 km/h -
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5) ARP (Active Roll-Over Protection
The ARP (Active Roll-over Protection) system is a safety assistant device that minimizes, by
controlling brakes and the engine, the physical tendency of the vehicle rollover during sharp lane
changes or U-turns. For the system, software is added to the existing ESP system and no
additional device or switch is needed. One must note that the ARP system, just as general
assistant devices including the ABS, is only a safety assistant device using the ESP system and its
function is useless when the situation overcomes the physical power. Following picture shows
how the ARP compensates the vehicle position by varying each wheel's braking power to
overcome the physical tendency of the vehicle rollover during sharp turns.
Lateral sensor
(In sensor cluster)
Vehicle speedBrake force
Radius
The vehicle driving condition is controlled by the internally programmed logic according to the
input signals from wheel speed sensor, steering angle sensor and lateral sensor.
During the ARP operation, vehicle safety (rollover prevention) takes the first priority and thus,
stronger engine control is in effect. Consequently, the vehicle speed decreases rapidly, so the
driver must take caution for the vehicle may drift away from the lane.