An internal combustion engine includes a port injection valve and a feed pump that pressurizes the fuel. An engine ECU performs a stuck abnormality diagnosis of the fuel pressure sensor based on detection values of the fuel pressure sensor in first processing and second processing. The first processing includes setting a target pressure of the fuel in the storage section to a first pressure, and detecting a pressure of the fuel with the fuel pressure sensor. The second processing includes setting the target pressure of the fuel in a low-pressure delivery pipe to a second pressure lower than the first pressure, and detecting a pressure of the fuel. The engine ECU causes the first processing to be performed in response to a start signal that starts an internal combustion engine, and causes the second processing to be performed subsequent to the first processing.