SsangYong Actyon Sports II. Manual - part 50

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2412-02

Collecting PM

→ Regeneration

The engine ECU detects the 
amount of PM collected by the 
information from the 
temperature sensors and 
differential pressure sensor. 
When the soot is accumulated, 
the engine ECU performs post-
injection to increase the 
exhaust gas temperature and 
burns the collected PM at 
approx. 600°C.

Oxidation (DOC)

When the exhaust gas enters 
into the CDPF assembly, its 
CO, HC and PM are reduced 
by the redox reaction of the 
DOC. The remaining PM is 
filtered and collected in CDPF, 
and the temperature of the 
exhaust gas is increased to 
between 450 and 500°C.

5. OPERATING PROCESS

[Configuration and principle of operation]

The exhaust gas 

passed through the 

exhaust manifold 

enters into the CDPF 

assembly (at approx 
250℃).

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1) Oxidation of DOC

The DOC oxidizes HC and CO of the exhaust gas in the two-way catalytic converter at 180℃ or 
more, and performs best at the temperature between 400 and 500℃. The front EGT sensor 

detects whether the DOC can burn (oxidize) the post-injected fuel or not, and sends the signal to the 
ECU to maintain the DOC operating temperature between 300 and 500℃. The DOC reduces CO 

and HC of the exhaust gas by redox reaction and also reduces small amount of PM.

1. Oxygen adheres to the catalyst materials: Less than 180℃

2. CO and HC are oxidized by the catalyst materials: More than 180℃

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2) Collecting PM of DPF

There is a filter installed in the DPF and the PM filtered by this filter is burned (regeneration) when the 

temperature of exhaust gas is increased due to post-injection. The filter has a honeycomb-like structure 

to capture the particulate matter and the inlet and outlet of each channel are closed alternatively. Once 

the exhaust gas enters to the inlet of a channel, it is released from the outlet of the adjacent channel 

through the porous wall because of the closed outlet of the first channel, and the PM is collected in the 

first channel.

[Collecting PM of CDPF]

Normally, when the driving distance becomes approx. 600 to 1,200 km, enough amount of soot to 

be burned is filtered and accumulated in the CDPF. The ECU increases the amount of fuel post-
injection to increase the temperature of the exhaust gas up to 600°C, so that the soot is 

burned. The soot is burned for 15 to 20 minutes (may differ by conditions).

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3) PM Regeneration of DPF

The differential pressure sensor installed in the DPF measures the pressure values of inlet and outlet of 

CDPF. And the amount of the PM collected in the filter is calculated based on the exhaust temperature, 

intake air mass flow, booster pressure, etc. 

The regeneration is started when the amount of the collected PM is 28 g or more. 
The ECU commands post-injection to increase the temperature of CDPF to 600℃.

When the amount of the collected PM is not enough: The DPF works as a filter. 

1.

When enough amount of PM is collected: The ECU commands post-injection and increase the exhaust 

gas temperature to start regeneration.

2.