Patent ID: 10113495

Abstract:
An exhaust gas recirculation device for an internal combustion engine includes: an opening command signal output unit 52 which outputs an opening command signal in relation to an EGR control valve on the basis of an operating condition of the internal combustion engine; a variation component separation unit 54 which separates the valve opening command signal from the opening command signal output unit 52 into a basic component and a variation component generated so as to be superimposed on the basic component; a variation component determination unit 56 which determines whether the EGR control valve is in a steady state or a transient state on the basis of a magnitude of the variation component separated by the variation component separation unit 54; and an EGR control valve diagnosis device 58 that performs an abnormality diagnosis on the EGR control valve when the variation component determination unit determines that the EGR control valve is in the steady state.