2012 SSANGYONG KORANDO Service Manual

04-6
1. OVERVIEW
The intake system for D20DTF engine is equipped with an electric throttle body which includes a flap.
This flap is controlled by an electrical signal to cut off the intake air entering to the engine when the
ignition switch is turned off. To be sure to get the optimized swirl in intake manifold, the swirl valve and
dual type port have been adopted. And, the improved HFM sensor has been adopted to control the
intake air volume more precisely.
2. COMPONENTS
1719-02 Swirl control valve
Operates variably in accordance with the engine
load and rpm.
* For more information, refer to Chapter "Engine
Control".
1719-01 Intake manifold
Passage for intake air during the operation of
variable swirl valve
1719-16 Electric throttle body
* For more information, refer to Chapter "Engine
Control".
2330-01 Intercooler assembly

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2313-15 HFM (Hot Film Air-Mass) sensor
HFM sensor, version 6
* For more information, refer to Chapter "Engine
Control".
2313-01 Air cleaner assembly and
resonator

04-8
3. INPUT/OUTPUT OF INTAKE SYSTEM

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4. OPERATING PROCESS
Work Flow ▶

04-10
1) Types of swirl
Swirl: One cylinder has two intake air ports, one is set horizontally
and the other one is set vertically. Swirl is the horizontal air flows in
cylinder due to the horizontal intake air ports.
Tumble: Tumble is the vertical air flows in cylinder due to the vertical
intake air port
Squish: Squish is the air flows due to the piston head. Normally, this
is appears at the final process of compression. In CRDi engine, the
piston head creates the bowl type squish.
2) Swirl control
In DI type diesel engine, the liquefied fuel is injected into the cylinder directly. If the fuel is evenly
distributed in short period, the combustion efficiency could be improved. To get this, there should be
good air flow in cylinder. In general, there are two intake ports, swirl port and tangential port, in each
cylinder. The swirl port generates the horizontal flow and the tangential port generates the longitudinal
flow. In low/mid load range, the tabgential port is closed to increase the horizontal flow. Fast flow
decreases the PM during combustion and increases the EGR ratio by better combustion efficiency.

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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.
3) 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. -
-
4) 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.

04-12
5. CIRCUIT DIAGRAM

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1. TROUBLESHOOTING
1) Work Flow