| 摘要 |
An abnormality diagnosis apparatus for diagnosing abnormality of a secondary air supply assembly includes an abnormality diagnosing unit, an air-fuel ratio learning/correcting unit, a learning degree computing unit, and a prohibition unit. The abnormality diagnosing unit diagnoses abnormality of the secondary air supply assembly based on an output of the air-fuel ratio detecting unit. The air-fuel ratio learning/correcting unit learns variation of an air-fuel ratio control system of the engine and corrects variation of an air-fuel ratio based on a result of learning the variation of the air-fuel ratio control system. The learning degree computing unit computes a learning degree, by which the air-fuel ratio learning/correcting unit learns the variation of the air-fuel ratio control system. The prohibition unit prohibits the abnormality diagnosis or makes a diagnostic result invalid when the learning degree is equal to or less than a predetermined value. |
