2012 SSANGYONG KORANDO engine

15-22
Load Engine speed Swirl
valveAmount of
swirlRemarks
Low speed,
Low loadbelow 3,000 rpm Closed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas)
High speed,
High loadover 3,000 rpm Open LightIncrease charge efficiency, higher
engine power
The variable swirl valve actuator operates when
turning the ignition switch ON/OFF position to
open/close the swirl valve. In this period, the soot
will be removed and the learning for swirl valve
position is performed.
Swirl valve
Swirl: This is the twisted (radial) air flow along the cylinder wall during the intake stroke. This stabilizes
the combustion even in lean air-fuel mixture condition.
e. Features
Swirl and air intake efficiency
To generate the swirl, the intake port should be serpentine design. This makes the resistance in air
flow. The resistance in air flow in engine high speed decreases the intake efficiency. Eventually, the
engine power is also decreased, Thus, the swirl operation is deactivated in high speed range to
increase the intake efficiency.
Relationship between swirl and fuel injection pressure
The injector for DI engine uses the multi hole design. For this vehicle, there are 8 holes in injector. If
the swirl is too strong, the injection angles might be overlapped and may cause the increased PM and
insufficient engine power. Also, if the injection pressure is too high during strong swirl, the injection
angles might be overlapped. Therefore, the system may decreases the fuel injection pressure when
the swirl is too strong. -
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f. Relationship between swirl and fuel injection pressure
The injector for DI engine uses the multi hole design. For this vehicle, there are 8 holes in injector. If
the swirl is too strong, the injection angles might be overlapped and may cause the increased PM and
insufficient engine power. Also, if the injection pressure is too high during strong swirl, the injection
angles might be overlapped. Therefore, the system may decreases the fuel injection pressure when
the swirl is too strong. -
Anti-knock methods:
Shorten the ignition timing by pilot injection, lessen the fuel injection volume during ignition delay
period.
Increase engine speed.
Maintain intake sir temperature with intercooler or glow plug device.
Increase intake air pressure with turbocharger.
Warm up engine to keep the normal operating temperature.
Increase compression ratio.
Use the fuel with high cetane. *
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HFM sensor
(intake air temp.)
Oxygen sensorD20DTF ECU
T-MAP sensor
(5) EGR control
a. Overview
The EGR (Electric-Exhaust Gas Recirculation) valve reduces the NOx emission level by recirculating
some of the exhaust gas to the intake system.
The major difference with the previous EURO 4 type, is that the DC motor with improved response rate
according to the EURO 5 regulation. The solenoid type actuator is used in the conventional model, but in
this new model, the DC motor type actuator with improved response rate is adopted. Also the hall senso
r
which provides a more stabilized signal than the potentiometer, and the EGR bypass flap which
improves engine warming up efficiency are also used. The HFM sensor and the position sensor are
used to feedback the amount of EGR for both EURO 4 and EURO 5.
b. Components
Electronic
throttle body
Coolant
temp.sensor
E-EGR valveCrankshaft posi.
sensor
Accelerator
pedalE-EGR cooler

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d. Bypass control for EGR cooler
1. Cooler temperature
<007e008f008c00950047009b008f008c0047008a00960096009300880095009b0047009b008c00940097008c00990088009b009c0099008c00470090009a00470089008c00930096009e0047005e00570b4500530047009b008f008c0047008c009f008f00
88009c009a009b0047008e0088009a00470090009a00470089>ypassed the EGR cooler.
2. Exhaust gas temperature
<007e008f008c00950047009b008f008c0047008c009f008f0088009c009a009b0047008e0088009a0047009b008c00940097008c00990088009b009c0099008c00470090009a00470089008c00930096009e0047005a005700570b4500530047009b008f00
8c0047008c009f008f0088009c009a009b0047008e0088009a> is bypassed the EGR cooler.
Otherwise, PM could be increased due to too low exhaust gas temperature.
e. Control elements for EGR system
Accelerator pedal (engine load) - Indicates the driver's intention and engine load. If the load goes up,
the EGR ratio is decreased.
T-MAP (boost pressure map stored in ECU) - Compensates the difference in boost pressure by
adjusting EGR ratio.
Engine rpm - Used as the signal for determining EGR operating range.
Coolant temperature - When the coolant temperature is low, NOx is decreased but PM could be
increased. So, to reduce PM, decrease EGR ratio when the coolant temperature is low.
Intake air mass and temperature - HFM sensor measures the intake air mass to calculate the actual
EGR volume. If the air mass is larger than programmed value in map, EGR ratio will be higher.
EGR position sensor - Detects the actual opening angle of EGR valve and performs feedback
function according to PWM control by ECU.
Wide band oxygen sensor - Detects the oxygen volume in exhaust gas to check if the EGR ratio is
proper.
Electronic throttle body - Keeps EGR ratio to optimized level by controlling the throttle body in EGR
operating range (decreasing pressure in intake manifold). -
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f. Features
As EGR ratio goes up, smoke volume will be
higher. But, this lowers the combustion chamber
temperature and accordingly the concentration of
NOx is decreased. The point with highest NOx is
immediately after TDC.As EGR temperature goes up, the
concentration of NOx will be higher. Thus, it is
necessary to cool down the exhaust gas.
However, during engine cooled, it may cause
large amount of PM. To prevent this, the
exhaust gas is bypassed the EGR cooler.

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Accelerator
pedal
(6) E-VGT control
a. Overview
E-VGT (Electric-Variable Geometry Turbine) turbocharger system in D20DTF engine uses the venturi
effect that controls the flow rate of exhaust gas by adjusting the passage in turbine housing. The newly
adopted DC motor actuator (E-actuator) controls the E-VGT system more precisely and faster. To get
the high operating power from turbine, the ECU reduces the exhaust gas passage In low speed range
and increases it in high speed range.
b. Components
E-VGT
actuator
Coolant
temperature
Front EGT
sensorT-MAP sensorCrankshaft pos,
sensor
HFM sensor
(intake air temp)
ECU
(D20DTF)

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d. E-VGT system control
Turbocharger system operates the E-VGT actuator according to the signals for engine epm, accelerator
pedal position, atmospheric pressure, T-MAP, coolant temperature and intake air temperature.
Turbocharger actuator is performed PWM control by ECU.
In general, the boost pressure feedbacks the turbocharger operation and the boost temperature is used
for calculating the precise density.
E-VGT provides higher engine power with faster reaction speed compared to conventional VGT.
Operating wave Vane Control
Low
speed
rangeIn low speed range:
retract the vane to
increase boost
pressure. The vane
has low (-) duty, and
the unison ring
moves to retract the
vane in weak PWM
signal.
High
speed
rangeThe unison ring
moves to extend the
vane in strong PWM
signal. Maximum
pressure is 3 bar
and the system
controls it according
to the input signals.

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HFM sensor
(air mass)
CDPF
(7) Wide band oxygen sensor
a. Overview
For diesel engine, combustion is not performed at the optimum (theoretically correct) air-fuel ratio and
the oxygen concentration is thin in most cases. So the wide-band oxygen sensor is used for this kind of
engine, and this sensor is a little different from the one that used for gasoline engine. The combustion in
diesel engine is controlled by fuel injection volume. Therefore, the wide band oxygen sensor should be
used in diesel engine. This sensor measures the air-fuel ratio in very wide range, and is also called full
range oxygen sensor.
The wide band oxygen sensor measures the oxygen density in exhaust gas and sends it to ECU to
control the EGR more precisely. -
b. Components
D20DTF
ECU
EGR valveElectronic
throttle bodyCoolant temp.
sensor
Oxygen
sensorInjector (C3I)