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 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 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 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: An electronic control unit diagnoses leakage abnormality in an intake system downstream from a supercharger provided in the intake system of the engine. The electronic control unit sets, as a supercharging region monitoring value, a ratio between a first air amount obtained from a detection value of an air flowmeter and a second air amount obtained from a detection value of an intake pressure sensor, the ratio being the ratio obtained when the engine is operated in a supercharging region. The electronic control unit also sets, as a non-supercharging region monitoring value, a ratio obtained when the engine is driven in a non-supercharging region. The electronic control unit determines the presence of the leakage abnormality in the intake system when the ratio of the supercharging region monitoring value to the non-supercharging region monitoring value is larger than a predetermined specified value.

Abstract: An electronic control unit diagnoses leakage abnormality in an intake system downstream from a supercharger provided in the intake system of the engine. The electronic control unit sets, as a supercharging region monitoring value, a ratio between a first air amount obtained from a detection value of an air flowmeter and a second air amount obtained from a detection value of an intake pressure sensor, the ratio being the ratio obtained when the engine is operated in a supercharging region. The electronic control unit also sets, as a non-supercharging region monitoring value, a ratio obtained when the engine is driven in a non-supercharging region. The electronic control unit determines the presence of the leakage abnormality in the intake system when the ratio of the supercharging region monitoring value to the non-supercharging region monitoring value is larger than a predetermined specified value.

Abstract: In an internal combustion engine that includes a first secondary air supply unit having a first air pump and a first air switching valve and a second secondary air supply unit having a second air pump and a second air switching valve, a time difference is provided between the operation start timing of the first air pump and the operation start timing of the second air pump, and the open timing of the first air switching valve and the open timing of the second air switching valve are set so as to be simultaneous with each other.

Abstract: In an internal combustion engine that includes a first secondary air supply unit having a first air pump and a first air switching valve and a second secondary air supply unit having a second air pump and a second air switching valve, a time difference is provided between the operation start timing of the first air pump and the operation start timing of the second air pump, and the open timing of the first air switching valve and the open timing of the second air switching valve are set so as to be simultaneous with each other.