Control system and method of internal combustion engine, for supressing load variation and improving self-diagnosis

摘要

A control system of an internal combustion engine in a vehicle, for improving the self-diagnosis accuracy and decreasing the frequency of stopping the self-diagnosis process, is disclosed. The system comprises a self-diagnosis section for executing self-diagnosis of the internal combustion engine; a load control section for controlling a load imposed on the internal combustion engine; and a normal driving control section for maintaining a normal driving state in which a variation of the load imposed on the internal combustion engine is suppressed, by operating the load control section while the self-diagnosis is being executed by the self-diagnosis section and while the current driving state of the vehicle is in a predetermined driving range.