Abstract: An EGR valve deterioration degree calculation system configured to calculate a degree of deterioration of an EGR valve includes an execution device. The execution device is configured to perform: a pressure acquisition process; a pressure change amount calculation process of calculating a pressure change amount associated with an operation of opening and closing the EGR valve; a differential pressure calculation process of calculating a differential pressure between an upstream side of the EGR valve and a downstream side of the EGR valve when the EGR valve is in a closed state; and a deterioration degree calculation process of calculating the degree of deterioration of the EGR valve based on the pressure change amount and the differential pressure.

Abstract: An EGR valve deterioration degree calculation system configured to calculate a degree of deterioration of an EGR valve includes an execution device. The execution device is configured to perform: a pressure acquisition process; a pressure change amount calculation process of calculating a pressure change amount associated with an operation of opening and closing the EGR valve; a differential pressure calculation process of calculating a differential pressure between an upstream side of the EGR valve and a downstream side of the EGR valve when the EGR valve is in a closed state; and a deterioration degree calculation process of calculating the degree of deterioration of the EGR valve based on the pressure change amount and the differential pressure.

Abstract: The fuel pressure sensor abnormality diagnosis apparatus diagnoses that a fuel pressure sensor is abnormal in the case where, because a state where a detected value of the fuel pressure sensor is less than a target value occurs, a fuel discharge amount of a fuel pump is increased, and as a result, the fuel discharge amount reaches its maximum amount, and even if a predetermined period has elapsed since the fuel discharge amount reaches its maximum amount, the detected value is less than the target value.

Abstract: A supercharging system includes a waste gate valve (35) mounted in a bypass passage (34) that bypasses a turbine (31) and through which exhaust gas flows. An electronic control unit (39) that diagnoses abnormality of the supercharging system makes a first abnormality determination and a second abnormality determination, each of which is based on an integrated value of an intake air amount and an increased amount of supercharging pressure in each of a first determination period from initiation to termination of an increase in the supercharging pressure and a second determination period from initiation to termination of an increase in the intake air amount.

Abstract: The fuel pressure sensor abnormality diagnosis apparatus diagnoses that a fuel pressure sensor is abnormal in the case where, because a state where a detected value of the fuel pressure sensor is less than a target value occurs, a fuel discharge amount of a fuel pump is increased, and as a result, the fuel discharge amount reaches its maximum amount, and even if a predetermined period has elapsed since the fuel discharge amount reaches its maximum amount, the detected value is less than the target value.

Abstract: A supercharging system includes a waste gate valve (35) mounted in a bypass passage (34) that bypasses a turbine (31) and through which exhaust gas flows. An electronic control unit (39) that diagnoses abnormality of the supercharging system makes a first abnormality determination and a second abnormality determination, each of which is based on an integrated value of an intake air amount and an increased amount of supercharging pressure in each of a first determination period from initiation to termination of an increase in the supercharging pressure and a second determination period from initiation to termination of an increase in the intake air amount.