SSANGYONG NEW REXTON 2012 Service Manual

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1. COMPONENTS
The components of the exhaust system for the D27DTP (POWER UP) engine have been changed
as follows:
1. E-EGR valve: Controlling the EGR valve electrically and sends the valve location signal to
ECU (vacuum modulator control has been deleted)
2. EGR cooler: Decreasing EGR gas (NOx) efficiently by cooling the EGR gas and let it flow to
the intake pipe
3. VGT turbocharger: Increase in capacity and performance compared to D27DTP & D20DT
engine
The EGR system has been changed to control NOx more efficiently and the VGT turbo charger
has been changed to increase the engine power. For more details, refer to the next description.
The exhaust system for D27DTP (POWER UP) engine is as follows:

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1. OVERVIEW FOR CDPF (EURO IV)
1) General Description
The CDPF (Catalyst & Diesel Particulate Filter) was installed to the Rexton II D27DTP engine
previously. However, it is now installed to the all 2009 DI engine models, except the
Actyon
Sports. The DI engine types installed to Rexton are D27DTP, D27DT and D20DT, and their CDPF,
related sensor and operation logic are the same.
This section describes the CDPF system (based on Euro IV) which is installed to the Rexton II
D27DTP engine (older model).
2) Compatibility of CDPF System by Vehicle Model
Rexton II: Same CDPF system for D27DTP and D27DT engines (including its components)
Kyron & Actyon: Same CDPF system for D27DT and D20DT engines (including its components)
The CDPF assemblies installed to the Euro IV D27DTP Rexton II and 2009 Rexton II are
different in their mounting layout, but their front/rear exhaust temperature sensors and
differential pressure sensors are same. -
3) System Met with Euro IV Regulations
E-EGR valve
EGR cooler
Engine ECU (Ver. 3.2)
HFM sensor
C3I injector
Electronic throttle valve (body)
Other engine mounting components -
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For details about the modified components and system related to the Euro IV regulations, refer to
the 2008 Rodius engine service manual.

2. CDPF(EURO IV) SYSTEM
The CDPF system is only installed to the D27DT engine, and the major changes comparing to the
previous D27DT engine is as follows:
CDPF (Catalyst & Diesel Particulate Filter) and sensors
Under air cleaner in righ
side of engine
compartment
As the soot is filtered in the CDPF, the pressure between the front side and the rear side of the
filter is different from each other. If the amount of soot is over 28 g, the soot is burnt in the
CDPF. The combustion is determined depending on the pressure difference, temperature of
exhaust gas and EGR ratio. According to these, the soot filtered by post injection of injector is
burnt at
CDPF Exhaust Gas Temperature Sensor
The two temperature
sensors inside the CDPF
are installed in exhaust
manifold (front exhaust
gas temperature sensor)
and in DOC (rear exhaust
gas temperature sensor),
and perform the following
functions.Front Exhaust Gas Temperatur
e
Sensor:Rear Exhaust Gas
Temperature Sensor:
Measures the exhaust gas
temperature of the exhaust manifold.
As it is installed in front of the VGT
turbocharger, it also monitors the
exhaust gas temperature coming to
the turbocharger. If the temperature
of the exhaust gas flowing to the
turbocharger is higher than the
specification, the engine lowers the
exhaust gas temperature.Measures the increased
exhaust gas temperature
after the oxidation process
of DOC. If the temperature
injection amount is
increased to increase the
temperature.
Front exhaust gas
temperature sensor

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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.

1. OVERVIEW
As the solution for environmental regulations and PM
(Particla Material) of diesel engine, the low emission
vehicle is getting popular. This vehicle is equipped with an
extra filter to collect the soot and burn it again so that the
amount of PM in the exhaust gas passed through the
DOC (Diesel Oxydation Catalyst) is reduced. The CDP
F
(Catalyst & Diesel Particulate Filter) is an integrated filter
including DOC (Diesel Oxydation Catalyst) and DPF
(Diesel Particulate Filter).
Regulated parts are carbon monoxide (CO), nitrogen oxide (NOx), particular matter (PM) and soot
in the exhaust emission, and the particulars of the regulations are prescribed in the following table.

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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. -

3. SOOT FILTERING AND BURNING PROCEDURES
1) Operating Procedures of CDPF
The most efficient and practical technology for now is adopted to the diesel particulate filter
(DPF).
This system collects the soot from the diesel engine to the filter and burns the soot so that over
than 95% of soot can be removed from the exhaust gas. However, the durability and the cost of
additional system remain as problems.
Firstly, the exhaust gas is passed through the DOC and its temperature is increased as it is
oxidized. The ECU detects the temperature change with two temperature sensors. The CO, HC
and partial particulate material are removed from the exhaust gas (this procedures are the sames
as the ones for the conventional DOC and no sensor is required).
After the exhaust gas is passed through the DOC and oxidized, most of the harmful material is
removed from the exhaust gas. However, to meet the environmental regulations in the future, the
soot is filtered and burnt again in DPF to decrease the particulate material further.
Rear exhaust gas temperature sensor
(Measuring temperature of exhaust gas
escaping DOC)
The filtered soot is burned whenever the vehicle is driven for 600 ~ 1200 km. The driving
distance can be differed depending on the vehicle's driving conditions. The soot is burnt
for 15 ~ 20 minutes. -

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Front temperature sensor
(Measuring the temperature of
exhaust gas passed through
exhaust manifold)
Differrential pressure sensor (Front
pressure port) Differrential pressure sensor (Rear
pressure port) Rear temperature sensor
(Measuring the temperature of exhaust gas
passed through DOC)
The exhaust gas enters
into CDPF assembly after
passing through the
exhaust manifold.
(Normal temperature of
exhaust gas: approx. The engine ECU detects
the amount of particulate
material colected by the
information from
temperature sensors and
differential pressure snesor.
When the soot is
accumulated, the pressure
difference between the
front and the rear side
occurs. Then, the engine
ECU performs the post
injection to raise the
exhaust gas temperature
and burn the collected soot
at approx. When the exhaust gas
enters into the CDP
F
assembly, its CO, HC and
particulate material are
reduced as it is oxidized in
DOC. The remaining
particulate material is
filtered and collected in
DPF and the temperature
of exhaust gas is
increased to approx. 450
~