| 摘要 |
PROBLEM TO BE SOLVED: To improve diagnostic accuracy, by ensuring a proper detection range relating to determination of failure in operation of a recirculation valve, according to a diagnostic device of an exhaust gas recirculation device. SOLUTION: A calculation means 3 is provided to calculate a physical quantity correlating with a flow rate of recirculation gas returned to an intake side through the recirculation valve 9. A change means 5 is provided to perform a change control for changing opening of the recirculation valve 9 to be a plurality of openings. A determination means 4 is provided to determine a state of the recirculation valve 9 based on a difference in recirculation physical quantity calculated by the calculation means 3, in each of the plurality of openings changed by the change control of the change means 5. COPYRIGHT: (C)2011,JPO&INPIT |
