2012 SSANGYONG NEW ACTYON SPORTS engine

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2) Operation of ESP System
The ESP (Electronic Stability Program) has been developed to help a driver avoid danger of losing
control of the vehicle stability due to understeer or oversteer during cornering. The yaw rate
sensor, lateral sensor and longitudinal sensor in the sensor cluster and the steering wheel angle
sensor under the steering column detect the vehicle conditions when the inner or outer wheels are
spinning during oversteer, understeer or cornering. The ESP ECU controls against oversteer or
understeer during cornering by controlling the vehicle stability using input values from these
sensors and applying the braking force to the corresponding wheels independently. The system
also controls the engine power right before the wheel spin synchronized with the ASR function to
decelerate the vehicle automatically in order to maintain the vehicle stable during cornering.
(1) Under steering
What is understeering? ▶
Understeer is a term for a condition in which the steering wheel is steered to a certain angle during
driving and the front tires slip toward the reverse direction of the desired direction. Generally,
vehicles are designed to have understeer. It is because that the vehicle can return back to inside of
cornering line when the steering wheel is steered toward the inside even when the front wheels are
slipped outward.
As the centrifugal force increases, the tires can easily lose the traction and the vehicle tends to slip
outward when the curve angle gets bigger and the speed increases.

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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.

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Circuit description ▶
When compared to the vehicle equipped with ABS/EBD only, the internal hydraulic circuit has a
normally-open separation valve and a shuttle valve in primary circuit and in secondary circuit.
When the vehicle brakes are not applied during engine running or when applying the non-ABS
operating brakes, the normally-open separation valve and the inlet valve are open, whereas the
normally-closed shuttle valve and the outlet valve are closed.
When the ESP system is operating, the normally-open separation valve will be closed by the
solenoid valve operation and the hydraulic circuit will be established by the shuttle valve. Then,
the inlet and outlet valves will be closed or open depending on the braking pressure RISE, HOLD
or DUMP conditions.
Flashing warning lamp and warning sound during ESP operation ▶
When the ESP operates while the vehicle is moving, the ESP warning lamp on the instrument
panel flickers and the buzzer sounds at every 0.1 second. The ESP lamp operation is to inform a
driver that the vehicle is extremely unstable.
The ESP system is just a supplementary system for the vehicle and it cannot control the vehicle
over the physical limit. Do not solely rely on the system but be advised to drive the vehicle safely.
Drive feeling during ESP operation ▶
When the ESP system activates, the driving feeling can be different depending on vehicle driving
conditions. For example, it will feel different when the ESP system is activated while the ABS is
operated by depressing the brake pedal and when the ESP system is in control without the brake
pedal depressed on the same curve.
If the ESP system operates with the brake applied, the brake pressure will be increased on the
corresponding wheel which already has braking pressure for the ESP controls. In other words, the
ESP system would make the driver feel more abruptly braked compared to the situation that the
braking pressure is applied to wheel which had no braking force.
Noise and vibration that driver senses during ESP operation ▶
The ESP system may transfer noise and vibration to a driver due to the pressure changes caused
by the motor and valve operations in a very short period of time.
Extreme cornering will trigger the ESP operation and this will make the driver sense noise and
vibration due to sudden brake application.
Also, the ESP system controls the engine power. Therefore, the driver may notice the engine
power decreases even when the accelerator pedal is depressed.

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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)
4. 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°. -
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Lock nut
Adjusting plug
Bushing
Rack support yokeRack support spring
Yoke plugLock nut

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The difference between both sides should
be within 0.6 kg.Park the vehicle on a paved and flat
ground and place the front wheels at
straight ahead direction.
Start the engine and let it run around 1,000
rpm.
Install the spring scale on the
circumference of the steering wheel and
measure the steering effort in both
directions. 1.
2.
3. Steering Effort Check ▶
Steering Angle Check ▶
Place the front wheel on a turning radius
measuring tool.
Turn the steering wheel to the its both
ends and measure the maximum steering
angle. 1.
2.
If the steering angle is out of the specified
value, check and adjust the toe-in.
Steering angleInner37.59˚
Outer33.48˚
Free Play Check ▶
Start the engine and place the wheels at
straight ahead direction.
Turn the steering wheel until the tires starts
to move and measure the distance on the
circumference of the steering wheel. 1.
2.
If the free play is out of the specified
value, check the free play in steering
column shaft connection and steering
linkage. Replace or repair if necessary.
Free play30 mm
Steering effort in
standstillbelow 3.0 kg

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Oil Change ▶
Open the power fluid reservoir cap and
drain the fluid completely with oil suction
device. To make it easy, turn the steering
wheel to its both ends several times.
Fill up the specified fluid into fluid reservoir
and bleed air from the steering system. 1.
2. Oil Level Check ▶
Place the vehicle on a level ground and
start the engine and let it run at idle speed.
Turn the steering wheel several times so
that the oil temperature reaches to normal
operating level (75~85˚C).
Place the steering wheel at straight ahead
direction.
Check the oil level in the power steering oil
reservoir. Adjust the oil level between MAX
and MIN. 1.
2.
3.
4.
If the difference between two
measurements is below 5 mm and the level
is between MAX and MIN level, it's normal.
If it is over 5 mm, bleed air from the
system. Check the fluid level on a level ground with
the engine turned off. The fluid level should
be between the MIN and MAX marks on the
reservoir cap gauge.
below 5 mm
Engine idling Engine running
Oil typeATF Dexron II or III
Capacityapprox. 1ℓ (including
reservoir)

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Air Bleeding ▶
Lift up the vehicle very carefully.
Turn the steering wheel to its both ends
several times and add the oil up to MAX
line in the steering oil reservoir.
Periodically crank the starting motor and
turn the steering wheel to its both ends
without any interruption.
Check the oil level again. If the oil level is
fluctuated, repeat the procedures from
step 3 to step 5.
Start the engine.
Turn the steering wheel to its both ends
until any bubble can be found in the
steering oil reservoir.
Perform the test drive and check the
steering wheel for normal operation and
noise.
If the oil level abruptly goes up, bleed the
air from the system again. 1.
2.
3.
4.
5.
6.
7.
8.
The air bleeding should be done after
servicing the power steering system and when
the difference between two measurements
(cooled and normal temperature) is
prominent.
Max
Min
Normal Abnormal
If the air bleeding is not properly
performed, the life span of the power
steering pump may be shortened. -

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Oil Pump Pressure Check ▶
Unscrew the pressure line fitting in power
steering pump.
Install the pressure gauge between the
power steering pump and the power
steering oil pressure line.
Place the shift lever to neutral position.
Apply the parking brake.
Open the valve in pressure gauge. Start
the engine and let it run at idle speed.
Turn the steering wheel several times so
that the oil temperature reaches to normal
operating level. 1.
2.
3.
4.
5.
Before checking the pressure, check the oil
level and belt tension. Prepare the empty
container to collect the spilled oil during the
service. Check the oil pump pressure to locate any
defect in oil pump.
Fully close the valve in pressure gauge and
measure the oil pressure. 6.
Relief pressure
90 ± 3 bar
Oil pump
Steering gear box
To prevent internal damage, do not close
the gauge valve over 10 seconds.
Keep the oil temperature at proper range. -
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