traction control SSANGYONG KORANDO 2012 Service Manual

07-4
1. OVERVIEW
The AWD system in this vehicle is the electronic 4WD system and controls the traction to rear wheels
according to the driving conditions.
1) Driving Mode
(1) AUTO mode (Normal driving mode)
Normally the vehicle is in 2WD mode.
Automatically change to this mode when the vehicle needs higher traction.
(2) LOCK mode (when pressing 4WD LOCK switch)
This mode provides the highest traction. Use
this mode when driving on unpaved, rugged,
steep, sandy, wet or slippery roads.
In 4WD LOCK mode, if the rear wheel speed
exceeds 40 km/h, 4WD LOCK mode is
canceled and 4WD AUTO mode is activated
(Indicator OFF). If the speed is decreased
below 35 km/h, 4WD LOCK mode is resumed
(Indicator ON again). -
-
Mode table ▶
4WD LOCK switch Vehicle speed Driving mode
Not pressed (4WD AUTO) No conditions 4WD AUTO
Pressed (4WD LOCK) over 40 km/h 4WD AUTO
Pressed (4WD LOCK) below 35 km/h 4WD LOCK

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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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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.