2012 SSANGYONG KORANDO power steering

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1. OVERVIEW
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 to decelerate the vehicle automatically in order to maintain the
vehicle stable during cornering.

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3. ESP OFF switch
Located on the left side of
instrument panel.2. Steering wheel angle
sensor
Located on column shaft with
contact coil.1. HECU assembly
Located under the power
steering fluid reservoir and
contains the pressure sensor.
2. COMPONENTS
4. Sensor cluster
Located on the floor under front
passenger seat.5. Wheel speed sensor
(4WD/2WD-front)
Located on knuckle. the
appearance of front sensor is
same with rear sensor.6. Rear wheel speed sensor
(2WD)
Located on knuckle. The
appearance is different from
that for 4WD.

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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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2. TIGHTENING TORQUE
Item Tightening torque Remark
1. Power steering reservoir mounting bolt 8.8 to 13.7 Nm 12 mm x 2 EA
2. Power steering
pumpUpper mounting bolt/nut25 ± 2.5 Nm13 mm x 1 EA
Lower mounting bolt25 ± 2.5 Nm12 mm x 2 EA
3. Oil pipe Eye bolt (pump side) 53.9 to 63.7 Nm 22 mm
Steering gear box side nut 31.4 to 37.2 Nm 17 mm
4. Oil pipe bracket mounting nut 6.8 to 10.8 Nm 10 mm
5. Tie rod end lock nut 44.1 to 53.9 Nm 17 mm
6. Tie rod nut 63.7 to 78.4 Nm 22 mm
7. Lower shaft Lower mounting bolt
(gear box side)17.6 to 24.5 Nm 12 mm
Upper mounting bolt (column
side)17.6 to 24.5 Nm 12 mm
8. Column shaft Lower mounting bolt 19.6 to 24.5 Nm 12 mm
Upper mounting nut 19.6 to 24.5 Nm 12 mm
9. Steering wheel nut 39.2 to 58.8 Nm 22 mm
10. Loosened gear box mounting bolt/nut Left: 98.0 to 127.4 Nm 17 mm
Right: 88.3 to 107.9 Nm 17 mm
11. Heat shield mounting bolt 8.8 to 13.7 Nm 12 mm x 2 EA

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3. DIFFERENCES BETWEEN HPS AND EPS
HPS EPS
1 Crankshaft pulley (DDU)
2 Auto tensioner
3 Tensioner pulley
4 Vacuum pump
5 A/C compressor pulley
6 Alternator pulley
7 Water pump pulley
8 No.1 idle pulley
9 No.2 idle pulley
10 Power steering pump -
HPS (Hydraulic Power Steering)EPS (Electric Power Steering)

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4. MAJOR CHANGES
1) Steering Heating System
Steering wheel heating unit
Old New
The steering wheel heated wire and the heating unit are
installed in the steering wheel assembly.Lower switch cluster
Old
New
The steering wheel heating switch has
been added on the lower switch cluster.
Specifications ▶
Description Specification
Power consumption Below 95W
Rated voltage 12V
Operating voltage 9V~16V
Rated current6±2.0A
Steering wheel
heating unit
Steering wheel
heating switch

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1. SYSTEM DESCRIPTION
The power steering has been designed to make the wheel move more easily than in a manual steering
system. The hydraulic power assists the process utilizing hydraulic fluid. The fluid increases pressure in
the power steering pump and aids the movement of the steering mechanism.
The power steering system consists of pump, oil reservoir, rack and gear box.
The power steering pump is a vane type and delivers hydraulic pressure to operate the power steering
system.
The pressure relief valve in the pump controls the discharging pressure.
The rotary valve in the rack and the pinion gear directs the oil from the power steering pump to one side
of the rack piston. The integrated rack piston converts the hydraulic pressure to linear movement. The
operating force of the rack moves the wheels through the tie rod, the tie rod end and the steering knuckle.
Even though the hydraulic pressure cannot be generated, a driver can steer the vehicle without power
assist but it needs very high steering force.
In this case, the operating force of the steering wheel is conveyed to the pinion, and the movement of the
pinion moves the rack through the pinion gear combined to the rack gear.