Exhaust gas recirculation fault detection system

摘要

An engine controller for an automotive engine having an inlet system and an exhaust system includes an EGR valve for permitting exhaust gas to flow from the exhaust system to the inlet system, and an engine controller for operating the EGR valve by closing it from its normal open position. The difference in exhaust gas pressures in an EGR line downstream of the EGR valve measured during the EGR valve normal open and closed positions is compared with first and second threshold values and the actual pressure with the EGR valve open is compared with a third threshold value to determine whether the EGR system is blocked.