The Diesel Particulate Filter System is to prevent Particulate Matter such as soot from being emitted into the atmosphere. The system consists of a filter assembly, exhaust gas temperature sensors and a pressure sensor.
The particulate filter is part of the Catalytic Converter which has a honeycomb structure that filters the Particulate Matter from the exhaust gasses, but other gases such as CO2 and NOx are passed through the filter.
Having too much soot in the filter means the system must be regenerated. The quantity of soot is measured by the engine's management system which automatically performs a regenerating process where necessary.
The quantity of soot collected in the filter is due to a number of things, such as the type of oil used in the engine. Kia vehicles fitted with a Catalytic Converter or Diesel Particulate Filter must use synthetic engine oil, so using the correct grade of oil is important.