Patent ID: 6102015
Filing Date: 2000-08-15
Classification: F02M

Abstract:
A diagnostic device for an exhaust gas recirculation system of an engine, comprising:an EGR passage, wherein the EGR passage recirculates exhaust gas from an exhaust passage to an intake passage;an EGR control valve disposed in the EGR passage;an EGR temperature sensor, disposed in the EGR passage, to detect a temperature; anda controller, wherein the controller comprises:a control section generating an operating signal to control the EGR control valve;a calculation section to calculate a rising rate of the temperature;a diagnostic execution section to execute a diagnosis of the exhaust gas recirculation system based on the temperature and the operating signal when the temperature is less than or equal to a predetermined temperature; anda permission section to permit execution of the diagnosis when the rising rate of the temperature is greater than a predetermined value even when the temperature is greater than the predetermined temperature.