Methods and systems are provided for indicating crankcase breach due to disconnection of a crankcase vent tube from an engine on a clean air side or broken crankcase vent tube. In one example, a maximum possible change in crankcase vent tube pressure is estimated for each pedal transient of a drive cycle. The change for a plurality of transients in averaged and compared to a threshold to identify vent tube disconnection.

A control system for an oil supply mechanism includes an oil pump, a hydraulic pressure sensor, a drive shaft, a pump pulley, a toothed belt, and an output shaft. An electronic control unit included by the control system detects an abnormality of the toothed belt based on a comparison result between an actual value and a theoretical value that are frequencies of pressure pulsations of oil. The actual value is a value calculated based on time fluctuations of a hydraulic pressure detected by the hydraulic pressure sensor. The theoretical value is a value calculated based on a rotational speed of the output shaft and the number of teeth of an inner rotor.

A vehicle cooling system comprises an oil circulation circuit in which a cooling oil is circulated by an electric oil pump to cool a predetermined cooling target with the cooling oil; an oil temperature sensor detecting an oil temperature that is a temperature of the cooling oil; and a control device including a cooling control portion outputting a rotation command for operating the electric oil pump so as to cool the cooling target. The control device includes a pump abnormality determination portion outputting the rotation command to the electric oil pump to determine a presence/absence of abnormality based on a rotation state of the electric oil pump when an operation stop time of the vehicle is longer than a predefined determination permission time and an oil temperature detection value detected by the oil temperature sensor is higher than a predefined determination permission temperature.

A vehicle cooling system comprises an oil circulation circuit in which a cooling oil is circulated by an electric oil pump to cool a predetermined cooling target with the cooling oil; an oil temperature sensor detecting an oil temperature that is a temperature of the cooling oil; and a control device including a cooling control portion outputting a rotation command for operating the electric oil pump so as to cool the cooling target. The control device includes a pump abnormality determination portion outputting the rotation command to the electric oil pump to determine a presence/absence of abnormality based on a rotation state of the electric oil pump when an operation stop time of the vehicle is longer than a predefined determination permission time and an oil temperature detection value detected by the oil temperature sensor is higher than a predefined determination permission temperature.

A diagnostic system for a lubrication circuit of an internal combustion engine of a vehicle. The system includes a viscometer for detecting the viscosity of a lubricating liquid of the lubrication circuit, a temperature sensor for detecting the temperature of the lubricating liquid, and a control unit to acquire the state of the lubricating liquid, given by the viscosity detected for a given lubricating liquid condition, which includes the lubricating liquid temperature and the date of last replacement of the lubricating liquid, and for a given condition of use of the engine, and to assess the state of the lubricating liquid by comparing the detected viscosity of the lubricating liquid with the viscosity reference values stored in the database in the same or similar condition of lubricating liquid temperature, date of last replacement of the lubricating liquid and use of the engine.

A method for diagnosing a failure of a solenoid valve of a piston cooling device is provided. The method includes varying a pressure in a variable proportional control oil pump when an opening command or a closing command of the solenoid valve is sent to inject oil from the piston cooling device. Additionally, a variation of an oil pressure in an oil flow path of the piston cooling device is monitoring according to a variation of the pressure in the variable proportional control oil pump and whether a failure occurs at the solenoid valve of the piston cooling device is then determined.

A method for diagnosing a failure of a solenoid valve of a piston cooling device is provided. The method includes varying a pressure in a variable proportional control oil pump when an opening command or a closing command of the solenoid valve is sent to inject oil from the piston cooling device. Additionally, a variation of an oil pressure in an oil flow path of the piston cooling device is monitoring according to a variation of the pressure in the variable proportional control oil pump and whether a failure occurs at the solenoid valve of the piston cooling device is then determined.

A replacement recommending device for a lubricant in an internal combustion engine in which a liquid gasket is applied to a sealing spot includes a processing circuit configured to perform an acquisition process of acquiring temperature information regarding the lubricant in the internal combustion engine, and an output process of outputting a signal indicating that replacement of the lubricant is recommended by operating an output device when a parameter is equal to or greater than a predetermined value based on the temperature information acquired in the acquisition process, the parameter having a value that increases with an increase in a cumulative time in which a temperature of the lubricant is equal to or higher than a prescribed temperature, and the cumulative time being a cumulative time based on a time point at which the liquid gasket is applied to the sealing spot.

A replacement recommending device for a lubricant in an internal combustion engine in which a liquid gasket is applied to a sealing spot includes a processing circuit configured to perform an acquisition process of acquiring temperature information regarding the lubricant in the internal combustion engine, and an output process of outputting a signal indicating that replacement of the lubricant is recommended by operating an output device when a parameter is equal to or greater than a predetermined value based on the temperature information acquired in the acquisition process, the parameter having a value that increases with an increase in a cumulative time in which a temperature of the lubricant is equal to or higher than a prescribed temperature, and the cumulative time being a cumulative time based on a time point at which the liquid gasket is applied to the sealing spot.

A control system for an oil supply mechanism includes an oil pump, a hydraulic pressure sensor, a drive shaft, a pump pulley, a toothed belt, and an output shaft. An electronic control unit included by the control system detects an abnormality of the toothed belt based on a comparison result between an actual value and a theoretical value that are frequencies of pressure pulsations of oil. The actual value is a value calculated based on time fluctuations of a hydraulic pressure detected by the hydraulic pressure sensor. The theoretical value is a value calculated based on a rotational speed of the output shaft and the number of teeth of an inner rotor.