SSANGYONG KYRON 2006, Repair Manual, Page: 398 / 1105

ABS/ESP SYSTEM
KYRON SM - 2005.09
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
12
4890
3. PRINCIPLE OF ESP
Understeer & Oversteer Control
ESP (Electronic Stability Program) recognizes critical driving conditions, such as panic reactions in dangerous
situations, and stabilizes the vehicle by wheel-individual braking and engine control intervention with no need for
actuating the brake. This system is developed to help the driver avoid the danger of losing the control of the vehicle
stability due to under-steering or over-steering 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 spin present at any wheels during over-steering, under-steering or
cornering. The ESP ECU controls against over-steering or under-steering during cornering by controlling the vehicle
stability using the input values from the sensors and applying the brakes independently to the corresponding wheels.
The system also controls during cornering by detecting the moment right before the spin and automatically limiting
the engine output (coupled with the ASR system).
Understeering
Understeering is when the steering wheel is steered to
a certain angle during driving and the front tires slip to-
ward the reverse direction of the desired direction.
Generally, vehicles are designed to have under steering.
The vehicle can return back to inside of cornering line
when the steering wheel is steered toward the inside
even when the vehicle front is 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.
Oversteering
Oversteering is when the steering wheel is steered to a
certain angle during driving and the rear tires slip out-
ward losing traction.
When compared with under steering vehicles, the con-
trolling of the vehicle is difficult during cornering and the
vehicle can spin due to rear wheel moment when the
rear tires lose traction and the vehicle speed increases.
Under Steering Over Steering
Braked
wheel
Compensating
yaw moment
Desired
course
With
ESP
Without
ESP
Braking
force
Braking
force
Desired
course
With
ESP
Braked
wheel
Without
ESP
Compen-
sating yaw
moment