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Vacuum pump drive
Intake/exhaust CamshaftsCamshaft sprocketFinger follower & HLA
Components
Cylinder head
Camshaft position sensorHP pump drive gear
Cylinder head gasket
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(5) High Pressure System Pressure Test
Fuel rail pressure test
Disconnect the fuel rail pressure sensor
connector and then IMV connector. 1.
Connect the pressure tester to the fuel rail
pressure sensor connector. 2.
Crank the engine 2 times for 5 seconds. 3.
Read the highest pressure value displayed
on the tester display.
If the highest pressure value is 1,050 bar or
less, refer to the section "Fuel System
Check Process". -
-
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0000-00
Static test for backleak of injector
Disconnect the injector return hose and cover
the openings with caps shaped screw (included
in the special tool). 1.
Connect the hose of the container for
measuring backleak to the return nipple of the
injector.
(prevent air entry to the low pressure line) 2.
Disconnect the IMV connector of the high
pressure pump and then fuel pressure
sensor connector. 3.
The connector of the injector can be easily
contaminated. Always keep it clean.
Crank the engine for 5 seconds.
Check the flow volume of injector backleak. 4.
5.
If the value is out of the specified range,
replace the injector.
Flow volume of injector
backleakbelow 20 cm
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HP pump pressure test
Prepare a special tool for high pressure test
and clean it thoroughly to prevent foreign
materials from entering. 1.
Disconnect the high pressure fuel supply pipe
on the HP pump and install the close rail in the
tool kit. 2.
Connect the other end of the close rail to the
fuel rail for test 3.
Disconnect the return hose for HP pump and
connect the clear hose and connect its the
other end to the return port of the fuel rail for
test. 4.
Connect the digital tester connector to the
sensor connector of the fuel rail for test.
Crank the engine 2 times for 5 seconds after
removing the IMV connector and fuel rail
pressure sensor connector.
Read the pressure value displayed on the
tester display is within the specified range. 5.
6.
7.
Specification1,050 bar or more
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ENGINE CONTROL
SYSTEM
Engine ECU (D20DTF)
1. OVERVIEW
The components in the fuel system supply fuel and generate high pressure to inject fuel to each injector.
They are controlled by the engine ECU.
The common rail fuel injection system consists of fuel tank, fuel line, low pressure line which supplies lo
w
pressure fuel to the low pressure pump (includes high pressure pump), high pressure line which
connected to the injector and the engine control unit (ECU) which calculates the accelerator pedal
position and controls the overall performance of vehicle based on the input signals from various sensors.
HP fuel pump
Common rail and
Injector Fuel filter
(Priming pump)
Fuel supply tube
Fuel return tube
Fuel tank Fuel neck
Fuel sender (main)
Fuel sender (sub)
Low pressure line
High pressure line
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Fuel rail assembly
Relieves the pulsation.
Measures the fuel pressure.
Distributes the fuel to injectors.Camshaft position sensor
Determines the injection order.
Injector (C3I)
Pre-injection, main injection, after-injection by
signals from ECU
Fuel tank
Fuel metering by dual sender. Supply the fuel in
main fuel tank and sub fuel tank through fuel
inlet tube
2. SYSTEM LAYOUT AND OPERATION
1) Layout
Fuel supply line
Fuel return line
For sensor and actuator control logic,
refer to Chapter "ENGINE CONTROL".
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0000-00
Crankshaft position sensor
Measuring engine rpmT-MAP sensor
Measuring booster pressure
and temperatureHFM
Measuring intake air mass and
temperature
Engine ECU (D20DTF)
Engine control by various
signals
High pressure pump
Generates the high pressurized fuel
and supply it.
Plunger type HP pump (1,800
bar)
Vane type transfer pump (6bar)
Accelerator pedal
position sensor
Detects driver's intention for
speed up/downFuel filter assembly
Supply clean fuel/fuel
heating/water separation by
priming pump
Page 252 of 1336

2) Fuel System Flow Diagram
The fuel from the fuel tank is supplied to the fuel heater of fuel filter/priming pump and then low pressure
generated by the low pressure pump (built into HP pump) is transmitted to the HP pump.
The fuel pressure at the HP pump is controlled by the IMV valve, and the maximum allowed pressure is
1,800 bar. The compressed fuel at the fuel pump is delivered to the rail, and injected by the injectors
according to the injection signals. The injection method is the same with the conventional method; Fuel
return by backleak which operates the needle valve.
The major difference is that the fuel return line is connected to the fuel filter inlet port, not the HP pump
venturi.
The pressure from the high pressure pump is increased to 1,800 bar from 1,600 bar, and the pump is now
installed to the cylinder head (cylinder block for previous model). The fuel pressure is generated by the
operation of intake camshaft and gears. The specifications for the IMV valve and the fuel temperature
sensor are not changed.