Page 209 of 600
D20DT Engine Remarks
HFM 6.0 HFM 6-ID
(Added digital signal function) -
Electrically controlled E-EGR valveECU controls the EGR valve directly.
It provides precise EGR control by
transmitting the electric signal of EGR
valve operating position. *
Vacuum modulator
Vacuum modulator for
turbocharger control
The vacuum modulator for controlling
EGR valve has been deleted. *
Throttle body is used to prevent the
engine from turning off with fluttering
noise at the moment the air to intake
manifold is blocked by closed flap
when the engine is switched off. *
Throttle body
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D20DT Engine Remarks
To enhance the EGR performance by
making the temperature of exhaust
gas into the intake manifold down, the
EGR cooler has been introduced. *EGR cooler
EGR GasCoolant
The throttle body and boost pressure
sensor have been installed on the
intake manifold. *
Intake manifold
Throttle
bodyBoost pressure sensor
Cylinder head
Coolant portTo enhance the cooling performance,
the coolant port has been introduced. *
To enhance the cooling performance,
the coolant passage has been made
in the cylinder block. *
Cylinder head gasket
Coolant passage
Page 211 of 600
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Injector (7-way Injection and C3I Coding)
1. FUEL SYSTEM - K2006
The C3I injector system is used in D20DT engine.
Injector
C3I Label
Two nozzle holes are added (currently 7) to the tip of the injector to increase the amount of fuel
injection and to improve injection efficiency according to the increased engine power.
The existing C2I coding (16 digits) is changed to C3I coding (20 digits) to monitor fuel injection and
follow the target value.
For the D20DT engine, the injector MDP (minimum current for the solenoid in the injector to lift the
nozzle) is leaned only when the engine is running. However, for the D20DT (EURO 4) engine, it is
learned when the vehicle is in motion and the engine is at idle speed. -
-
C3I Label
C3I Code
Fuel nozzle
holes (7)
C3I
Fuel nozzle
holes (7)
C3I Code (20 digits)
Page 212 of 600

1. FUEL FLOW OF D20DT (EURO 4) ENGINE
According to input signals from various sensors, engine ECU calculates driver's demand (position of the
accelerator pedal) and then controls overall operating performance of engine and vehicle on that time. ECU
receives the signals from sensors via data line and then performs effective engine air-fuel ratio controls
based on those signals. Engine speed is measured by crankshaft speed (position) sensor and camshaft
speed (position) sensor determines injection order and ECU detects driver's pedal position (driver's
demand) through electrical signal that is generated by variable resistance changes in accelerator pedal
sensor. HFM (Hot Film Air Mass) sensor detects intake air volume and sends the signals to ECU.
Especially, the engine ECU controls the air-fuel ratio by recognizing instant air volume changes from air flow
sensor to decrease the emissions (EGR valve control). Furthermore, ECU uses signals from coolant
temperature sensor and air temperature sensor, booster pressure sensor and atmospheric pressure sensor
as compensation signal to respond to injection starting, pilot injection set values, various operations and
variables.
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HP PumpFuel Line
Injector (7-way Injection and C3I Coding)Fuel filter Priming Pump
Common Rail
2. COMPONENTS OF FUEL SYSTEM
Fuel nozzle
holes (7)
Injector
Fuel pipe
High pressure fuel pip Fuel rail pressure sensor
Fuel filter
Connector
Priming
pump
Fuel from
HP pumpFuel filter
HP pumpFuel tank
Fuel tank
Common rail
Fuel return
port
Low pressure
fuel supply port
Venturi
High pressure
fuel supply port
(orifice included)
Fuel
temperature
sensor
IMV valve
Fuel return
port
IMV
connector
Page 214 of 600
3. HYDRAULIC CYCLE IN FUEL LINE
(TRANSFER AND HIGH PRESSURE LINE)
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3. Connection on EGR pipes4. Clamp on inlet hose to intake
manifold and inlet hose to
intercooler
1. TIGHTENINF TORQUE
The hose clamps and fasteners should be tightened to the specified tightening torque when
installing/removing the engine and/or components for intake system.
1. Hose between air cleaner and
turbocharger2. Hose between turbocharger and
intercooler
Page 216 of 600
HFM Sensor (ver. 6.0)VGT Turbo Chargera
Uncompressed air
Air coeaner Turbo
charger
Temperature
sensor
Pretension
graph
Ambient air
Air cleaner
Compressed air
1. INTAKE SYSTEM LAYOUT
The intake system 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.
And, the improved HFM sensor has been adopted to control the intake air volume more precisely.
Exhaust manifold
Air coeaner
Intercooler Exhaust gas
VGT control actuator