Patent ID: 8240298
Filing Date: 2012-08-14
Classification: F01N,F02D,G01M,Y02A,Y02T

Abstract:
1. An abnormality diagnosis apparatus for diagnosing abnormality of a secondary air supply assembly for an internal combustion engine of a vehicle that has an on-board battery, wherein an air-fuel ratio detecting means is provided to an exhaust gas passage of the internal combustion engine to detect an air-fuel ratio based on exhaust gas, and the secondary air supply assembly supplies secondary air to the exhaust gas passage at a position upstream of the air-fuel ratio detecting means, the abnormality diagnosis apparatus comprising: abnormality diagnosing means for diagnosing abnormality of the secondary air supply assembly based on an output of the air-fuel ratio detecting means; air-fuel ratio learning/correcting means for learning variation of an air-fuel ratio control system of the internal combustion engine and for correcting variation of an air-fuel ratio based on a result of learning the variation of the air-fuel ratio control system; learning degree computing means for computing a learning degree, by which the air-fuel ratio learning/correcting means learns the variation of the air-fuel ratio control system; and prohibition means for prohibiting the abnormality diagnosing means from diagnosing the abnormality of the secondary air supply assembly or for making a diagnostic result by the abnormality diagnosing means invalid when the learning degree computed by the learning degree computing means is equal to or less than a predetermined value.