Abstract: A controller for an internal combustion engine is configured to execute a determination process that determines that a deviation between a first change amount and a second change amount during a fuel cutoff operation is less than or equal to a threshold, and an anomaly diagnosing process that determines that an exhaust purification device is in a detached state when the determination process determines that the deviation is less than or equal to the threshold. The first change amount and the second change amount are change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively. The controller is configured to interrupt the determination process when the upstream-side temperature increases within a determination period.

Abstract: A controller for an internal combustion engine is configured to execute a determination process and an anomaly diagnosing process. The determination process is a process of determining that a deviation between a first change amount and a second change amount during a fuel cutoff operation is less than or equal to a threshold. The anomaly diagnosing process is a process of determining that an exhaust purification device is in a detached state when it is determined in the determination process that the deviation is less than or equal to the threshold. The first change amount and the second change amount are change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively.

Abstract: A controller for an internal combustion engine is configured to execute a regeneration process of burning and removing particulate matter accumulated in an exhaust purification device, a determination process of determining that a deviation between a first change amount and a second change amount is less than or equal to a threshold, the first change amount and the second change amount being change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively, and an anomaly diagnosing process that determines that the exhaust purification device is in a detached state when the determination process determines that the deviation is less than or equal to the threshold. The controller is configured to not execute the determination process during a period from the end of the regeneration process to when a post-regeneration execution condition is met.

Abstract: A controller for an internal combustion engine is configured to execute a regeneration process of burning and removing particulate matter accumulated in an exhaust purification device, a determination process of determining that a deviation between a first change amount and a second change amount is less than or equal to a threshold, the first change amount and the second change amount being change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively, and an anomaly diagnosing process that determines that the exhaust purification device is in a detached state when the determination process determines that the deviation is less than or equal to the threshold. The controller is configured to not execute the determination process during a period from the end of the regeneration process to when a post-regeneration execution condition is met.

Abstract: A controller for an internal combustion engine is configured to execute a determination process that determines that a deviation between a first change amount and a second change amount during a fuel cutoff operation is less than or equal to a threshold, and an anomaly diagnosing process that determines that an exhaust purification device is in a detached state when the determination process determines that the deviation is less than or equal to the threshold. The first change amount and the second change amount are change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively. The controller is configured to interrupt the determination process when the upstream-side temperature increases within a determination period.

Abstract: A controller for an internal combustion engine is configured to execute a determination process and an anomaly diagnosing process. The determination process is a process of determining that a deviation between a first change amount and a second change amount during a fuel cutoff operation is less than or equal to a threshold. The anomaly diagnosing process is a process of determining that an exhaust purification device is in a detached state when it is determined in the determination process that the deviation is less than or equal to the threshold. The first change amount and the second change amount are change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively.

Abstract: An electronic control unit calculates a rotation variation amount ??NE as a cetane number index value of the fuel supplied to an internal combustion engine and executes fuel injection control in a first execution mode corresponding to the rotation variation amount ??NE (S407, S408). In a mixing period in which the cetane number of the fuel supplied to the internal combustion engine is changed due to the fuel feed into the fuel tank (S401: YES), the fuel injection control is executed in a second execution mode such that, compared with the first execution mode, stable operation of the internal combustion engine is given more importance (S402:YES, S403). When calculation of the rotation variation amount ??NE is executed during the mixing period (S404: YES), fuel injection control is executed while limiting the reflection of the rotation variation amount ??NE (S405, S406).

Abstract: An electronic control unit calculates a rotation variation amount ??NE as a cetane number index value of the fuel supplied to an internal combustion engine and executes fuel injection control in a first execution mode corresponding to the rotation variation amount ??NE (S407, S408). In a mixing period in which the cetane number of the fuel supplied to the internal combustion engine is changed due to the fuel feed into the fuel tank (S401: YES), the fuel injection control is executed in a second execution mode such that, compared with the first execution mode, stable operation of the internal combustion engine is given more importance (S402:YES, S403). When calculation of the rotation variation amount ??NE is executed during the mixing period (S404: YES), fuel injection control is executed while limiting the reflection of the rotation variation amount ??NE (S405, S406).

Abstract: If an exhaust throttle valve changes to ON state from OFF state under a filter regeneration control condition for regenerating a PM filter, a differential pressure sensor detects a change of a differential pressure following an operation of the exhaust throttle valve. An increase in an exhaust backpressure is calculated based upon the change in the differential pressure. If the increase in the exhaust backpressure is lower than a predetermined value, the operation of the exhaust throttle valve is determined to be malfunctioning.

Abstract: If an exhaust throttle valve changes to ON state from OFF state under a filter regeneration control condition for regenerating a PM filter, a differential pressure sensor detects a change of a differential pressure following an operation of the exhaust throttle valve. An increase in an exhaust backpressure is calculated based upon the change in the differential pressure. If the increase in the exhaust backpressure is lower than a predetermined value, the operation of the exhaust throttle valve is determined to be malfunctioning.