•  The intake air amount is controlled to provide better recirculation of the exhaust gas.

•  The intake air amount to the engine is reduced to increase the exhaust gas temperature easily while the diesel particulate filter is carrying out combustion. Due to this, the particulate matter (PM) collected in the diesel particulate filter is burned and eliminated.

•  The valve is closed to cut the intake air when the engine switch is off to reduce the shock when the engine is turned off.