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11-34890-10
1. SPECIFICATION
1) Specification of Active Wheel Sensor
Description Specification Remark
Supplying voltage 4.5 ~ 16.0V
Output current (at 2.75 km/h of vehicle
speed)7mA(Lo) ~ 14mA(Hi)
Tightening torqueFront: 7.8 to 11.8 Nm
Rear: 7.8 to 11.8 Nm
Operating temperature-40 ~ 150℃
Operating frequency 1 ~ 2,500Hz
UnitDescription
Specification
ABS ESP
HECU Clock frequency: 32 MHz Clock frequency: 50 MHz
Memory: 128 KB Memory: 256 KB
Wheel speed
sensorActive type Active type Output: 7~14 mA
Steering wheel
angle sensorNone Max. detection angle speed:
1500 °/SecPulse duty:
50±10%
Operating voltage: 9 to 12 V
Sensor cluster None Yaw rate sensor + lateral G
sensor + longitudinal G sensor
(4WD)Mounting
direction should
be kept (CAN
communcation)
Longitudinal G
sensor4WD only None
Pressure sensor None HECU integrated
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11-10
3. FUNCTION
1) Term Definition
ABS: Anti-Lock Brake System ▶
When the brake pedal is abruptly depressed, the HECU calculates the slip ratio of each wheel based on
information received from the wheel speed sensors and controls the hydraulic module data quickly and
precisely in order to maintain the friction between the road surface and tire optimal (static friction).
Therefore, by keeping the friction between the road surface and tire optimal, it is possible to obtain
following effects: Enhanced steering stability, improved direction stability, reduced stopping distance and
etc.
EBD: Electronic brake-Force Distribution ▶
This is to detect the tire speed from the wheel speed sensor in order to supply the braking pressure to
the rear tires individually. In other words, the HECU measures the tire deceleration speed continuously
and controls the rear inlet valve on the hydraulic modulator to obtain optimal braking force as much as
possible. Thereby, stopping distance, braking effect and straight stability are improved.
ESP: Electronic Stability Program ▶
This is used to make the vehicle stabilized to recognize the emergency driving conditions, and to control
the brake for each wheels and the engine power when the brake system or acceleration will not work
any more in dangerous circumstances.
TCS: Traction Control System ▶
When the wheel is slipping due to an excessive engine torque while starting off or driving, this controls
the driving force (braking force + engine torque) in order to prevent the wheel from slipping through the
engine or brake control.
AYC: Active Yaw Control ▶
This has been developed to help a driver avoid danger of losing control of the vehicle stability due to
understeer or oversteer during cornering, which is a part of the ESP function.
HBA: Hydraulic Brake Assistant ▶
Developed based on the fact that elderly drivers depress the brake pedal too soft even when hard
braking is necessary, this an assist system to operate the HECU drive motor immediately and apply high
braking force to the wheels when the brake pedal is depressed softly and the vehicle should be braked
in emergency.
ARP: Active Rollover Protection ▶
This is a supplementary device for safety in ESP system and can help minimize the rollover accidents by
detecting a potential rollover situation through the brake and engine control when making sudden lane
change or turning sharply by adding only the software, without any separate device or switch.
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12-154610-01
Adjusting Plug
Gear Preload Check ▶
Preload is the term used in mechanical engineering to describe the load applied to a fastener merely as
a result of being fastened (and before any external loads are applied)
5. INSPECTION AND MAINTENANCE
Place the wheels at straight ahead direction.
Lift up the vehicle with a lift.
Unscrew the adjusting plug lock nut.
Measure the torque of the adjusting plug. 1.
2.
3.
4.
If the torque is excessive or too low, adjust to
the specified torque. 5.
Place the rack gear to the center position.
Tighten the adjusting plug to 10.2 Nm.
Turn the pinion gear so that the rack gear is
turned to lock to lock 5 times.
Unscrew the adjusting plug.
Tighten the adjusting plug to 4.6 to 5.6 Nm.
Unscrew the adjusting plug to 67.5°. -
-
-
-
-
-
Lock nut
Adjusting Plug
Bushing
Rack support yokeRack support spring
Yoke plugLock nut
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14-174170-09
If weight is not equally distributed around the wheel, unbalance centrifugal force by the wheel rotation
produces vibration. As the centrifugal force is produced proportional to the square of the rotating speed,
the wheel weight should be balanced even at high speed. There are two types of the tire and wheel
balancing: static and dynamic. Abnormal vibration may also occur due to unbalanced rigidity or size of
tires.
Static Balance ▶
When the free rotation of the wheel is allowed,
the heavier part is stopped on the bottom if the
wheel weight is unbalanced and this is called
"Static Unbalance". Also, the state at which tire's
stop position is not same is called "Static
Balance" when the wheel is rotated again. If the
part A is heavier as shown in the figure 1, add
the balance weight of a weight corresponding to
unbalanced weight from B to A to maintain the
static balance. If the static balance is not
maintained, tramping, up and down vibration of
the wheels, occurs.
Dynamic Balance ▶
The static unbalance of the wheel creates the
vibration in the vertical direction, but the dynamic
unbalance creates the vibration in the lateral
direction. As shown in the figure 2 (a), if two
parts, (2) and (3), are heavier when the wheels
are under the static balance condition, dynamic
unbalance is created, resulting in shimmy, left
and right vibration of the wheels, and the torque
Fxa is applied in the axial direction. To correct
the dynamic unbalance, add the balance weight
of a same weight for two points of the
circumference of the rim, A and B, as shown in
the figure 2 (b), and apply the torque in the
opposite direction to the torque Fxa to offset in
order to ensure smooth rotation of the wheel.
Center
A
B
(a) (b)
[Figure 1]
[Figure 2]
3. WHEEL BALANCE