CONTROLLER FOR INTERNAL COMBUSTION ENGINE

Processing circuitry controls a fuel injection amount of a direct injection valve provided in an internal combustion engine that uses hydrogen as fuel. An amount of combustion gas that flows back into the direct injection valve due to occurrence of pre-ignition is defined as a backflow amount. A single combustion cycle starting from a cylinder where fuel injection is performed subsequent to a cylinder where the pre-ignition has occurred is referred to as a subsequent cycle. The processing circuitry is configured to execute a process that reduces the fuel injection amount in the subsequent cycle when the backflow amount is relatively small compared with when the backflow amount is relatively large.