Patent ID: 8639411

Claim:
A method for diagnosing a fault of an oil piston cooling jets valve of an internal combustion engine, the method comprising the steps of: sensing a value of pressure in a main oil gallery with a sensor; checking a commanded state of the oil piston cooling jets valve, the commanded state being a first state for opening a communication between the main oil gallery and an auxiliary oil gallery or a second state for closing the communication; checking whether a value of pressure in the auxiliary oil gallery exceeds a predetermined threshold value thereof, above which a jet nozzle of the auxiliary oil gallery automatically opens; identifying, with an electronic control unit (ECU), a fault of the oil piston cooling jets valve when the value of pressure in the main oil gallery exceeds the predetermined threshold value by a predetermined quantity and when a result of the checking in the auxiliary oil gallery indicates that the oil piston cooling jets valve is in a different state than the commanded state.