2013 SSANGYONG KORANDO Service Manual

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.

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3) Vehicle Control During Cornering
The figure below shows the vehicle controls by the ESP system under various situations such as when
the brake pedal is depressed or not depressed during cornering, when the ABS is operating and when
braking without the ABS. It also includes the vehicle conditions when the TCS, a part of the ESP system,
is operating.
Condition Understeer control Oversteer control
Only ESP in
operation
No braking by driver
ESP
+
Normal braking
(no ABS operation)
ESP
+
ABS brake
ESP + ASR

4) HBA (Hydraulic Brake Assist System)
(1) Purpose
HBA (Hydraulic Brake Assist) system helps in an emergency braking situation when the driver applies
the brake fast, but not with sufficient pressure, which leads to dangerously long braking distance. ECU
recognizes the attempt at full braking and transmits the signal calling for full brake pressure from the
hydraulic booster. An inexperienced, elderly or physically weak driver may suffer from the accident by not
fully pressing the brake pedal when hard braking is required under emergency. The HBA System
increases the braking force under urgent situations to enhance the inputted braking force from the driver.
Based on the fact that some drivers depress the brake pedal too soft even under when hard braking is
necessary, the HECU system is a safety supplementary system that builds high braking force during
initial braking according to pressure value of the brake pressure sensor and the pressure changes of the
pressure sensor intervals. When the system is designed to apply high braking force when brake pedal is
depressed softly by an elderly or physically weak driver, the vehicle will make abrupt stopping under
normal braking situation due to high braking pressure at each wheels.
(2) Operation
The brake pressure value and the changed value of the pressure sensor are the conditions in which the
HBA System operates. There are 2 pressure sensors under the master cylinder. When the ESP ECU
system determines that emergency braking is present, the pump operates, the brake fluid in the master
cylinder is sent to the pump and the braking pressure is delivered to the wheels via the inlet valves . If the
drive depress the brake pedal slowly, the pressure change is not high. In this case, only the conventional
brake system with booster is activated.
(3) Operating conditions
Sensor pressure: over 40 bar
Pressure changes: over 850 bar/sec
Vehicle speed: over 30 km/h -
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-

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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.

6) HSA (Hill Start Assist)
The HSA (Hill Start Assist) prevents the vehicle from rolling backward by supplying the hydraulic
pressure to the wheels by the HECU after the brake pedal is released when starting off on uphill.

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7) Emergency Hazard Flasher Control (Coupled with ABS)
(1) System layout
(2) Emergency stop signal function
When ABS system is operating (or sudden braking), the hazard warning flashers will blink for 10
seconds to inform the emergency situation to the vehicles behind.
(3) Operating process
When receiving the emergency stop signal through PCAN communication it blinks with the interval of 4
Hz and when receiving the emergency stop OFF signal through PCAN communication it blinks with the
interval of 1.25 Hz, normal operating speed.
However, the manual operation of the switch has a priority over this function.
flasher

The BCM flashes the emergency auto hazard flasher with interval of 1.25 times/sec.:
The emergency hazard flasher does not operate if the vehicle speed is over 50 km/h when the
emergency stop signal is received.
The emergency hazard flasher operates if the vehicle speed is 50 km/h or lower when the
emergency stop signal is received.
When vehicle speed increases more than 10 km/h above the speed when the signal is received
during operation by emergency braking signal, the emergency hazard flasher stops operation.
When turning emergency hazard flasher switch OFF during operation by emergency braking signal,
it stops operation.
It is deactivated automatically 10 seconds after if items 2) and 3) above are not met during operation
by emergency braking signal.
If multi-function automatic hazard flasher signal is received during operation by emergency braking
signal, it will be overridden. -
-
-
-
-
-

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6. HYDRAULIC CIRCUIT OF ESP
MCP: Master Cylinder Primary
MSP: Master Cylinder Secondary
ESV: Electric Shuttle Valve
NO: Normal Open
NC: Normal Close
LPA: Low Pressure Accumulator