SSANGYONG NEW REXTON 2012 Service Manual

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1. OVERVIEW FOR CDPF (EURO IV)
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
type sinstalled 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 D27DTPengine (older model).
1) General Description
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
The Ssangyong vehicles installed with the D27DT engine manufactured from July 2007 to December
2007 comply with the EURO IV regulations. Modified components from the old engine model are as
follow:
- E-EGR valve
- EGR cooler
- Engine ECU (Ver. 3.2)
- HFM senso
- C3I injector
- Electronic throttle valve (body)
- Other engine mounting components
For details about the modified components and system related to the EURO IV regulations, refer to the
2008 Rodius engine service manual.

Under air cleaner in right side
of engine compartment
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
Front exhaust gas
temperature sensor
CDPF Exhaust Gas Temperature Sensor
The two temperature sensors
in-side the CDPF are installed
inexhaust manifold (front
exhaustgas temperature
sensor) and inDOC (rear
exhaust gas tempera-ture
sensor), and perform the fol-
lowing functions.Front Exhaust Gas Tempera-ture
Sensor:
Measures the exhaust gas tem-
perature of the exhaust manifold. As it
is installed in front of the VGT
turbocharger, it also monitors the
exhaust gas tempera-ture 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.Rear Exhaust Gas Tempera-
ture Sensor:
Measures the increased ex-
haust gas temperature after
the oxidation process of DOC.
If the temperature is below
amount is increased to
increase the temperature.
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

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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
Turbocharger may become weaker if high tem-
perature exhaust gas passes through the tur-
bocharger for DPF regeneration process.
The front exhaust gas temperature sensor moni-tors
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.Front exhaust gas
temperature sensor

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 CDPF (Catalyst & Diesel Particulate
Filter) is anintegrated filter including DOC (Diesel Oxydation
Catalyst) and DPF (Diesel Particulate Filter).
Comparison of throttle body functions based on exhaust emission regulation
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) General Description
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. -

2) System 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.
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 ai
r
are controlled. It is to raise the temperature by increasing the amount of fuel while decreasing the
amount of intake air.

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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
remainas 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 fo
r
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.
The filtered soot is burned whenever the vehicle is driven for 600 ~ 1200 km. The driving distance
can be differed depending on the
driving conditions. The soot is burnt for 15 ~ 20
minutes. -Exhaust
gas
Rear exhaust gas temperature
sensor(Measuring temperature of
exhaust gas escaping DOC)

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Front temperature sensor
(Measuring the temperature of
exhaust gas passedthrough
exhaust manifold)Rear temperature sensor
(Measuring the temperature of exhaust
gas passed through DOC)
Differrential pressure sensor
(Front pressure port)Differrential pressure sensor
(Rear pressure port)
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 be-tween the front
and the rear side occurs.
Then, the engineECU
performs the post injec-tion to
raise the exhaust gas
temperature and burn the
collected soot at approx. The exhaust gas enters
intoCDPF assembly after
passing through the exhaust
manifold. (Normal
temperature of ex-haust gas: When the exhaust gas
enters into the CDPF
assembly, its CO, HC and
particulate mate-rial are
reduced as it is oxi-dized in
DOC. The remaining
particulate material is
filtered and collected in
DPF and the temperature
of exhaust gas is increased

2) Fuel Injection During CDPF Regeneration
3) Warning Lamp Related To CDPF
CDPF regeneration process (warning lamp NOT illuminated)
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 in-formed with this operation by an
y
engine warning lamp or vehicle signal, so he/she may not
detect this operation. The control logic at the post-injection
dur-ing 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 tem-perature of the
exhaust gas. The driver may not feel any particular difference
from the vehicle.
No illumination