Abstract: An upstream integrated value is an integrated value of a difference obtained by subtracting an upstream gas temperature at a starting point in time of integration from the upstream gas temperature after starting of the internal combustion engine. A downstream integrated value is an integrated value of a difference obtained by subtracting a downstream gas temperature at the starting point in time of the integration from the downstream gas temperature after the starting of the internal combustion engine. An anomaly diagnosing process obtains an anomaly determination result indicating that the exhaust purification device is in a removed state when a deviation between the upstream integrated value and the downstream integrated value is smaller than a reference level. The determination threshold is higher than a dew point.

Abstract: A controller for an internal combustion engine includes processing circuitry. The processing circuitry executes a selecting process that selects one of a multi-injection process or a single injection process. The multi-injection process includes executing an intake synchronous injection and an intake asynchronous injection. The single injection process includes executing the intake asynchronous injection. In the intake synchronous injection, the fuel is injected in synchronization with a period in which an intake valve is open. In the intake asynchronous injection, the fuel is injected at timing advanced from timing of executing the intake synchronous injection. The processing circuitry changes ignition timing to a retarded side value in accordance with switching from execution of the multi-injection process to execution of the single injection process.

Abstract: A controller for an internal combustion engine includes processing circuitry. The processing circuitry executes a selecting process that selects one of a multi-injection process or a single injection process. The multi-injection process includes executing an intake synchronous injection and an intake asynchronous injection. The single injection process includes executing the intake asynchronous injection. In the intake synchronous injection, the fuel is injected in synchronization with a period in which an intake valve is open. In the intake asynchronous injection, the fuel is injected at timing advanced from timing of executing the intake synchronous injection. The processing circuitry changes ignition timing to a retarded side value in accordance with switching from execution of the multi-injection process to execution of the single injection process.