2012 SSANGYONG NEW ACTYON SPORTS Service Manual

15-26
LoadEngine speed Swirl valveAmount of
swirlRemarks
Low speed,
Low loadbelow 3,000
rpmClosed 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: 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.
Swirl valve
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 EGR
To reduce Nox, it is essential to increase EGR ratio. However, if EGR ratio is too high, the PM
also could be very higher. And, the exhaust gas should be evenly mixed with newly aspired air.
Otherwise, PM and CO are dramatically increased in highly concentrated exhaust gas range
and EGR ratio could not be increased beyond a certain limit. If the swirl valve operates in this
moment, the limit of EGR ratio will be higher. -
-
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.

15-270000-00
(9) 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.
To meet Euro-V regulation, the capacity and response rate of E-EGR valve in D20DTR engine
have been greatly improved. The EGR cooler with high capacity reduces the Nox, and the bypass
valve reduces the CO and HC due to EGR gas before warming up.
Also, the engine ECU adjusts the E-EGR opening by using the air mass signal through HFM
sensor. If the exhaust gas gets into the intake manifold when the EGR valve is open, the amount
of fresh air through HFM sensor should be decresed.
B. Components
E-EGR cooler
Accelerator pedal
moduleD20DTR ECU
Coolant
temperature senso
r
Oxygen sensor
HFM (intake air
temperature)Electric throttle
body
Crankshaft position
sensor
E-EGR valve
T-MAP sensor

15-28
C. Input/Output of E-EGR system

15-290000-00
D. Bypass control for EGR cooler
Cooler temperature ▶
<007e008f008c00950047009b008f008c0047008a00960096009300880095009b0047009b008c00940097008c00990088009b009c0099008c00470090009a00470089008c00930096009e0047005e00570b4500530047009b008f008c0047008c009f008f00
88009c009a009b0047008e0088009a00470090009a00470089>ypassed the EGR cooler.
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). -
-
-
-
-
-
-

15-30
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.

15-310000-00
(10) 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
HFM (intake air
temperature)
Front EGT sensor
E-VGT actuatorAccelerator pedal
module
Crankshaft position
sensor
Oxygen sensor
T-MAP sensor
Coolant
temperature senso
r
D20DTR ECU

15-32
C. Input/Output for E-VGT system

15-330000-00
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.