Page 1121 of 1336
2) Specification of Steering Wheel Angle Sensor
Description Specification
Operating voltage 9 to 16 V
Maximum output current 10 mA
Maximum detection angle speed
Operating temperature
Supplying voltage 9 to 16 V (battery voltage)
Output voltage (HI) approx. 3.50 V (3.0 to 4.1 V)
Output voltage (LO) approx. 1.50 V (1.3 to 2.0 V)
Pulses/rev 45 pulses/rev
3) Specification of Sensor Cluster
Description Specification
Supplying voltage approx. 12 V (8 to 16 V)
Current consumption below 250 mA -
Operating range Yaw rate sensor
Lateral/longitudinal sensor
Page 1122 of 1336
0000-00
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.
Page 1123 of 1336
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.
Page 1128 of 1336

0000-00
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.
Page 1129 of 1336

ESP controls during understeer
The ESP system recognizes the directional angle with the steering wheel angle sensor and senses the
slipping route that occurs reversely against the vehicle cornering direction during understeer with the ya
w
rate sensor and lateral sensor. Then, the ESP system applies the braking force to the rear inner wheel to
compensate the yaw moment value. In this way, the vehicle does not lose its driving direction and the
driver can steer the vehicle as intended.
(2) Over steering
What is oversteering?
Oversteer is a term of a condition in which the steering wheel is steered to a certain angle during driving
and the rear tires slip outward losing traction.
Compared to understeering vehicles, it is hard to control the vehicle during cornering and the vehicle can
spin due to rear wheel moment when the rear tires lose traction and the vehicle speed increases.
ESP controls during oversteer
The ESP system recognizes the directional angle with the steering wheel angle sensor and senses the
slipping route that occurs towards the vehicle cornering direction during oversteer with the yaw rate
sensor and lateral sensor. Then the ESP system applies the braking force to the front outer wheel to
compensate the yaw moment value. In this way, the vehicle does not lose its driving direction and the
driver can steer the vehicle as intended.
Page 1132 of 1336

0000-00
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.
Page 1145 of 1336
0000-00
1. SPECIFICATION (HPS)
Component Item Specification
Steering wheel Type 3-spoke
Outside diameter
Number of revolutions 3.09 rotations
Heated wire Simple ON/OFF
Gear box Type Rack and pinion
Gear ratio 46.94
Rack stroke
Steering angle Inner
Outer
Wheel alignment Toe-in
Oil pump Type Vane (removable pump and reservoir)
Maximum pressure
Displacement
Pulley diameter
Steering column Tilting angle Up + 2.0 deg
Down - 3.0 deg
Lower shaft Type Ball slip
Steering oil Oil type S-PSF 3
Oil reservoir capacity
Change interval EU (Diesel): Check and add at every 20,000
km
GEN (Diesel, Gasoline): Check and add at
every 15,000 km
Turning capability Min. turning radius 5.35 m
Page 1146 of 1336
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/nut
13 mm x 1 EA
Lower mounting bolt
12 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 49.1 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