Control device for internal combustion engine

A control device for an internal combustion engine, in which an exhaust pipe connected to an engine body is provided with a filter that traps particulate matter (PM), the control device including a PM regeneration function to regenerate the filter that has trapped the PM, the control device comprising a processor, the processor is electrically connected to

• an airflow meter configured to detect an amount of intake air that is fed to the engine body,
• a throttle valve opening degree sensor configured to detect an opening degree of a throttle valve configured to adjust an amount of the intake air,
• a first pressure sensor configured to detect a pressure upstream of the filter, and
• a second pressure sensor configured to detect a pressure downstream of the filter,
• wherein the processor is configured to:
• acquire a first PM accumulation amount, which is an amount of PM estimated to be accumulated on the filter before a regeneration, using an estimation model that takes detection values of the airflow meter and the throttle valve opening degree sensor as parameters;
• determine whether the first PM accumulation amount is equal to or more than a first predetermined value;
• acquire a pre-regeneration filter differential pressure that is a front-rear differential pressure of the filter before the regeneration, from the detection values of the first pressure sensor and the second pressure sensor, in response to determining that the first PM accumulation amount is equal to or more than the first predetermined value;
• acquire a second PM accumulation amount, which is an amount of PM estimated to accumulate on the filter after start of operation of the PM regeneration function, using the estimation model;
• determine whether the second PM accumulation amount is equal to or less than a second predetermined value, which is smaller than the first predetermined value;
• acquire a post-regeneration filter differential pressure that is a front-rear differential pressure of the filter after the regeneration, from the detection values of the first pressure sensor and the second pressure sensor, in response to determining that the second PM accumulation amount is equal to or less than the second predetermined value;
• acquire a pre-post regeneration differential pressure difference that is a difference between the pre-regeneration filter differential pressure and the post-regeneration filter differential pressure;
• determine an abnormality in the PM regeneration function in a case where the pre-post regeneration differential pressure difference is equal to or less than a threshold value set in advance;
• and
• display a warning indicating the abnormality in the PM regeneration function in response to determining that the PM regeneration function is abnormal.