Engine control system with exhaust gas recirculation and method for determining proper functioning of the EGR system in an automotive engine

摘要

An engine control 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 opening the valve during successive test periods separated by non-uniform intervals, while measuring engine speed response to the opening of the EGR valve so as to diagnose an improperly operating EGR valve.