fuel SSANGYONG NEW REXTON 2012 Owners Manual

2) Common Rail
The orifice is added to the connection to
the fuel pipe of the HP pump to prevent
the fuel pulsation by the fuel supply and
fuel cut according to the increase of
injected fuel volume. (It is also installed on
the connection of the high pressure fuel
supply line of the HP pump.)D27DTP & D27DT (EU IV)
D27DT

1881-09
3) Fuel Rail - Chrome Color
D27DTP & D27DT (EU IV)
Common rail)
D27DT
Common rail)The I.D and O.D of the fuel rail between
HP pump and common rail are increased
according to the increased amount of fuel
injection.
Also, the engine ECU, HFM sensor and
EGR system are changed to control the
fuel injection volume and engine more
precisely.

2. COMPONENTS OF FUEL SYSTEM

1881-09
Fuel Supply System

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Throttle Body
CDPF system controls the amount of intake air by
controlling the electronic throttle body. The electronic
throttle body has the following main functions.
CDPF control - added a function that increases the
exhaust gas temperature by closing the throttle valve
flap to minimize the intake air amount by the fuel
injection amount during the CDPF regeneration range
with the low engine load range.
ON/OFF control - prevents the engine from turning off
with vibration and noise by closing the throttle body flap
to block the intake air when the engine is stopped.
Duty control - controls the valve inside the throttle body
to burn more EGR gas in the EGR valve operating range.
VGT Turbocharger and Front Exhaust Gas Temperature Sensor
Front exhaust gas
temperature sensorTurbocharger may become weaker if high
temperature exhaust gas passes through the
turbocharger for DPF regeneration process.
The front exhaust gas temperature sensor monitors
the temperature of the exhaust gas that flows into
the turbocharger.
If the temperature of the exhaust gas that passes
through the exhaust manifold is higher than the
specification, the ECU decreases the fuel injection
amount and increases the EGR gas intake amount
to decrease the exhaust gas temperature.

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2. CDPF (EURO IV) SYSTEM CONTROL
1) Combustion Temperature and Procedures
As the soot is filtered in the CDPF, it is burnt and removed, and the CDPF is returned to the initial
state to collect the soot. Therefore, the burning procedures in the CDPF can be called as
regeneration.
The CDPF assembly is integrated with DOC (at front side) and DPF (at rear side).
The DPF burns the soot with high-temperature exhaust gas (over
The rear exhaust gas
temperature sensor monitors the temperature of DPF section. If this temperature is below the
regeneration temperature, the ECU increases the post injection period to increase the fuel
injection amount, and consequently to increase the exhaust gas temperature.
Front exhaust gas temperature sensor
(Measuring temperature of exhaust gas in
exhaust manifold)
Rear exhaust gas temperature sensor
(Measuring temperature of exhaust gas escaping DOC)
Normally, when the vehicle is driven for 600 ~ 1,200 km, the enough amount of soot to be
burnt is filtered and accumulated in the CDPF. The ECU increase the amount of post
injection to increase the tempeature of exhaust gas up to
so that the soot is burnt.
The soot is burnt for 15 ~ 20 minutes. -

3) Post Injection and Air Mass Control
When the differential pressure sensor detects the pressure difference between the front and the
rear side of CDPF, the sensor sends signal indicating the soot is acumulated and the post
injection is performed to raise the temperature of exhaust gas. The amount of fuel injected is
determined according to the temperature of exhaust gas detected by the rear temperature sensor.
If the temperature is below
the amount of fuel injected is increased to raise the
temperature. If the temperature is over
the amount of fuel injected is decreased or not
controlled.
When the engine is running in low load range, the amount of post injection and the amount of
intake air are controlled. It is to raise the temperature by increasing the amount of fuel while
decreasing the amount of intake air.
2) Sytem Composition for Soot Combustion
When the engine is running in low load range, the temperature of exhaust gas is decreased as the
amount of fuel supplied is decreased. To burn the soot filtered in the CDPF, the control system
should be installed to check the operating range and increase the temperature of exhaust gas by
controlling the amount of fuel supplied and intake air.
Two temperature sensors and one differential pressure sensor monitor the CDPF's operating
range. According to these sensors' information, the throttle flap decreases the intake air entered
to the throttle body. Also, the fuel injection pattern is added to increase the temperature of
exhaust gas for soot combustion.
There are three fuel injection patterns (pilot injection, pre-injection and main injection). As the
CDPF is installed, the post injection pattern is added.

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Throttle bodies by engine type
The throttle valve is controlled by electric signals sent from the engine ECU for optimal
fuel injection volume, engine load and effective combustion of EGR gas according to
the Euro 4 regulations. It has following functions by the engine type. -

2) Fuel Injection During CDPF Regeneration
3) Warning Lamp Related To CDPF
The CDPF system enters the regeneration mode when
the driving distance becomes approx. 600 to 1,200 km
(may differ by the driving condition and driving style).
Then, the engine ECU performs the CDPF regeneration
operation. However, the driver is not informed with this
operation by any engine warning lamp or vehicle
signal, so he/she may not detect this operation. The
control logic at the post-injection during the
regeneration process is to increase the fuel injection
volume and control the intake air volume (by the throttle
body) in order to increase the temperature of the
exhaust gas. The driver may not feel any particular
difference from the vehicle.
No illuminating

3) Guidelines on Engine Service
To prevent personal injuries and vehicle damages that can be caused by mistakes during engine
and unit inspection/repair and to secure optimum engine performance and safety after service
works, basic cautions and service work guidelines that can be easily forgotten during engine
service works are described in.
Cautions before service works
For safe and correct works, you must observe the working procedures and instructions in this
manual. And, use the designated tools as follow:
Engine stand / Heavy duty engine jack
To prevent the engine from starting abruptly, do not allow anybody to get in the vehicle while
servicing in engine compartment.
Before work on engine and electrical equipment, be sure to disconnect battery negative (-)
terminal.
Before service works, be sure to prepare the works by cleaning and aligning work areas.
Do not allow the foreign material get into the fuel injection system.
When removing the engine, use only the safety hook on engine and engine hanger. Do not
support the bottom of oil pan with a jack. -
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Completely drain the engine oil, coolant and fuel from engine before removal.
Before disassembling/assembling the engine components, carefully read the working
procedures in this manual.
Make sure to keep the specified tightening torques during installation.
Clean and properly lubricate the parts before reassembly.
Carefully check that there is not any interference while servicing. -
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