• The exhaust valve is opened during the intake stroke according to the engine operation conditions.
• The PCM controls the exhaust valve open/close during the intake stroke by operating the OCV and switching the engine oil passages based on the engine operation conditions.
• By opening the exhaust valve during the intake process, high temperature exhaust gas flows back (inside EGR) and the temperature of the air in the cylinder is raised to realize combustion stability during cold temperatures.
• During DPF regeneration control (auto DPF regeneration control), supply of high temperature exhaust gas to the DPF is required, external EGR is inhibited by the EGR valve and EGR cooler bypass valve operation, and NOx is reduced by introducing internal EGR.