The Diesel Particulate Filter (DPF) system prevents Particulate Matter (PM) from being discharged to the atmosphere and consists of a filter assembly, two Exhaust Gas Temperature Sensor (EGTS) and a Differential Pressure Sensor (DPS).The filter is integrated in the catalytic converter assembly and has honeycomb cell structure which can filter the PM in the exhaust gas. While the exhaust gas passes the DPF, the PM is gathered in the DPF and the others (CO2, NO, etc.) are discharged to the atmosphere via muffler. This gathered PM in DPF is called "soot".

If there are much soot in the DPF, the DPF must be regenerated. ECM can calculate amount of the soot by using the DPS signal, vehicle mileage or simulation data. If the ECM determines the DPF is need to regenerate, it will perform "Regeneration Procedure" when the vehicle condition is corresponded with the predetermined one (Regeneration Mode).

To burn the soot, the ECM injects additional fuel in the cylinders during exhaust stroke (two Post Injection) and increases the exhaust gas temperature to burning temperature of the soot (above 600℃). At this time, the soot are burn and its ash remains in the DPF as a result of the combustion.

5.

Engine Coolant Temperature ＞ 40℃