METHOD AND APPARATUS FOR DETECTING ABNORMALITY OF ENGINE

摘要

PROBLEM TO BE SOLVED: To accurately detect a cylinder-to-cylinder gap abnormality of an air-fuel ratio depending on the individual difference of air-fuel ratio detection means, in an abnormality detection method for detecting the cylinder-to-cylinder gap abnormality of the air-fuel ratio. SOLUTION: The method for detecting abnormality in an engine 1 detects the cylinder-to-cylinder gap abnormality of the air-fuel ratio of supplied mixed gas, based on an output value of a linear O2sensor 47. Under a predetermined first condition, the output characteristic of the linear O2sensor 47 is measured. A correction value for correcting the output of the linear O2sensor 47 depending on the individual difference of the linear O2sensor 47 is calculated by comparing the measured output characteristic and a preset reference characteristic. Then, under a predetermined second condition, the output value of the linear O2sensor 47 is corrected based on the calculated correction value. The cylinder-to-cylinder gap abnormality of the air-fuel ratio of the supplied mixed gas is detected based on the corrected output value of the linear O2sensor 47. COPYRIGHT: (C)2011,JPO&INPIT