DEGRADATION FAILURE DIAGNOSTIC DEVICE FOR EXHAUST GAS SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a failure diagnostic device for an exhaust gas sensor having high detection accuracy with respect to degradation failure of the exhaust gas sensor and suppressing increase in exhaust gas components during detection.;SOLUTION: The degradation failure diagnostic device for the exhaust gas sensor generates outputs in accordance with the exhaust gas components of an internal combustion engine. The degradation failure diagnostic device for the exhaust gas sensor is equipped with a detection signal generating means generating a signal for detection and calculating basic fuel injection amount including the signal for detection by multiplying the basic fuel injection amount by the signal for detection; a feedback representative value computing means computing a feedback representative value based on a feedback correction coefficient and calculating final fuel injection amount for inputting to the internal combustion engine by multiplying the basic fuel injection amount including the signal for detection by the feedback representative value; and an exhaust gas evaluating means extracting frequency response corresponding to the signal for detection from outputs of the exhaust gas sensor of the internal combustion engine with respect to the final fuel injection amount and determining a state of the exhaust gas sensor based on the frequency response.;COPYRIGHT: (C)2005,JPO&NCIPI