SsangYong Korando III (2010 year). Service manual — part 40

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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 low

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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Crankshaft position sensor

Measuring engine rpm

T-MAP sensor

Measuring booster pressure
and temperature

HFM

Measuring intake air mass and
temperature

Engine ECU (D20DTF)

Engine control by various
signals

Fuel filter assembly

Supply clean fuel/fuel
heating/water separation by
priming pump

Accelerator pedal

position sensor

Detects driver's intention for
speed up/down

High pressure pump

Generates the high pressurized fuel
and supply it.

Plunger type HP pump (1,800

bar)

Vane type transfer pump (6bar)

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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.