2012 SSANGYONG NEW REXTON differential

Diff. pres. sensor: Measure
pressure between front
side and rear side of CDPF
ECU (DCM 3.7)
Injector: Control post
injection
D. Operation process
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 accumulated 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
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.
Front EGT sensor:
Measure DOC temp.
Rear EGT sensor: Measure
DPF temp.
Electronic throttle
body: Control intake
air mass
T-MAP sensor
Intake air
mass
Exceed PM
limitBooster
pressure/
temperaturePost injection
Control intake
air mass

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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 -
-
-
-
-
-
-
For details about the modified components and system related to the Euro IV regulations, refer to
the 2008 Rodius engine service manual.

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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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
~

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If the CDPF cannot reach the regeneration
temperature due to low speed driving or other
reason during the regeneration process, the soot
is continuously accumulated in the CDPF. When
this condition continues and the CDPF is
overloaded with soot, the engine warning lamp
blinks to inform this situation to the driver.
In order to solve this problem, drive the vehicle at
a speed of approx. 80 km/h for 15 to 20 minutes
to perform the CDPF regeneration process.
If the engine warning lamp on the instrument
cluster blinks, the CDPF is overloaded. In this
case, perform the step 2. 1.
2.
3.
If the vehicle is driven at a speed of 5 to 10 km/h
for an extended period of time, the soot
accumulated in the CDPF cannot be burnt as the
CDPF cannot reach the regeneration temperature.
Then, an excessive amount of soot can be
accumulated in the CDPF.
This case is much worse than the simple overload
of the CDPF. To inform this to the driver, the
engine warning lamp comes on and the engine
power is decreased to protect the system.
To solve this problem, blow soot between the
engine and exhaust system several times and
erase the related DTC. Then, check if the same
DTC is regenerated again. If so, check the DTC
related to the differential pressure sensor. 1.
2.
3.
Actually, the DTC for the CDPF is generated more often by the component related to the CDP
F
system, such as the differential pressure sensor, than by excessive soot in the CDPF.
Illuminating
Blinking

4. COMPONENTS OF CDPF SYSTEM
Engine compartment
(RH)
Differential Pressure Sensor
Front Exhaust Gas
Temperature SensorThrottle Body
Front exhaust gas
temperature sensor