SsangYong Actyon Sports II. Manual - part 49

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Differential pressure 

sensor

Calculates the amount of 

PM collected by reading the 

pressure difference between 

before and after the CDPF.

Engine ECU 

DCM 3.7

Post-injection

Throttle

 valve

Regulates the rate of air 

intake.

CDPF

DOC+DPF

Front temperature 

sensor

Protects the turbocharger.

Rear temperature sensor

Measures the temperature 

of fuel combustion.

2. COMPONENT

For details, refer to section "Engine Control".

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3. INPUT/OUTPUT DEVICES

Front temperature sensor: This sensor is installed at the inlet of DOC and detects whether the 

DOC can burn (oxidize) the post-injected fuel or not.

Rear temperature sensor: This sensor is installed at the inlet of DPF and monitors that the 
temperature of the exhaust gas is kept at 600℃.

1.

2.

If the temperature exceeds 600℃, the life of CDPF can be reduced. So the amount of fuel 

post-injection is decreased.
If the temperature drops under 600℃, the rate of regeneration can be decreased. So the 

amount of fuel post-injection is increased.

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Differential pressure sensor: This sensor checks the amount of PM collected by calculating the 

pressure difference between before and after the CDPF.

Electric throttle valve: This valve reduces the intake air flow to raise the temperature of the exhaust 

gas when the CDPF is operating during idling.

3.

4.

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4. POST-INJECTION AND AIR MASS CONTROL

A DPS (Differential Pressure Sensor) measures the pressure difference between before and after the 

CDPF and detects whether the soot is collected in the CDPF or not. If PM is collected in the CDPF (In 

this case the pressure difference between before and after the CDPF exceeds the specified value. 

Normally, the system sends the signal when the driving distance becomes approx. 600 to 1,200 km), the 

temperature of exhaust gas is increased and the post-injection is started for regeneration. The amount of 

fuel post-injection is controlled by the exhaust gas temperature measured by the rear temperature 
sensor. If the temperature is less than 600℃, the amount of post-injection is increased to 

increase the regeneration temperature. Otherwise, the fuel injection amount is decreased or the fuel is 

not injected.

When the engine is running with low load, the intake air amount is also controlled as well as fuel injection 

amount. This function is used to increaser the combustion temperature by increasing the amount of fuel 

post-injection with the lowest air amount within the specified control logic.

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Front temperature sensor

Measures the temperature of 

exhaust gas.

This sensor is located at the rear 
side of exhaust manifold and 
monitors the temperature of 
combusted gas to prevent the 
exhaust system from overheating. 
When the temperature gets higher, 
this sensor cuts off the fuel delivery 
and controls the EGR to lower the 
temperature.

Rear temperature sensor

Measure the outlet 

temperature of DOC.

This sensor is located at the 
rear side of DOC and 
monitors the overheating of 
CDPF and post injection 
volume.

Engine ECU (D20DTR)

Differential pressure sensor

Measures the difference between 

inlet and outlet pressures of CDPF.

If the difference is higher than the 
specified value when collecting the 
PM, this makes the post injection for 
forced recycling of PM.

T-MAP sensor

Intake air 

mass

Measures 

the 

excessive 

amount of 

PM.

Boost 

pressure/

temperature

Injector (C31)

Controls the post injection.

Electric throttle body

Controls the intake air mass.

HFM sensor

Wide band 

oxygen sensor