Anomaly diagnostic apparatus for an internal combustion engine and an abnormality diagnostic method for an internal combustion engine

摘要

An abnormality diagnosis apparatus for an internal combustion engine (20) is provided. The abnormality diagnosing apparatus includes an ECU (50) configured to perform a temperature increasing operation to increase a temperature of a catalyst. The ECU is configured to determine whether the internal combustion engine is in an abnormal state. The ECU is configured to store the following values (i) to (iv) in the abnormal state: (i) a rotational speed of the internal combustion engine, (ii) a load of the internal combustion engine, (iii) a coolant temperature, (iv) an execution state indicating whether the temperature increase operation is being performed. The ECU is configured to determine whether the internal combustion engine has returned from the abnormal state to the normal state based on an actual rotational speed of the internal combustion engine, an actual load of the internal combustion engine, an actual coolant temperature, and an actual execution state of the temperature increase process.