A fault diagnosis apparatus of a coolant circulation system for a vehicle includes: a water pump for circulating coolant; a controller for applying a revolutions per minute (RPM) command to the water pump; a water pump driver for operating the water pump depending on the applied RPM command; and a current sensor for sensing an current input to the water pump driver. The controller determines whether the input current sensed by the current sensor is within a predetermined normal range to determine whether the coolant circulation system is failed or not.

The present disclosure provides a method of determining a coolant condition of a vehicle, and more particularly, a method of accurately determining a coolant condition, e.g., a condition in which gas is present in a system and an insufficient coolant condition without a separate additional sensor in a vehicle using an electric water pump (EWP). To this end, the present disclosure provides a method of determining a coolant condition of a vehicle, including, in a vehicle including an electric water pump (EWP) for circulating a coolant, acquiring driving state information of a water pump while the water pump is driven, by a controller, calculating a ripple value of a driving state from the acquired driving state information of the water pump, by the controller, and comparing the calculated ripple value with a reference value to determine a condition of a coolant, by the controller.

A method for coolant pump flow rationalization using coolant pump parameters includes calculating a first pump coolant flow based on a coolant input pressure sensor signal and the coolant pump speed. Further, the method includes calculating a second pump coolant flow based on coolant pump current and coolant pump speed when the first pump coolant flow is greater than a predetermined threshold; and comparing the first pump coolant flow with the second pump coolant flow to rationalize the coolant pressure sensor signal.

A method for coolant pump flow rationalization using coolant pump parameters includes calculating a first pump coolant flow based on a coolant input pressure sensor signal and the coolant pump speed. Further, the method includes calculating a second pump coolant flow based on coolant pump current and coolant pump speed when the first pump coolant flow is greater than a predetermined threshold; and comparing the first pump coolant flow with the second pump coolant flow to rationalize the coolant pressure sensor signal.

A cooling apparatus may be configured to cool a device mounted in a vehicle. The cooling apparatus may include: a pump configured to circulate a refrigerant between the device and a radiator, and a controller configured to provide an output command value to the pump, and to monitor occurrence of abnormality of the pump. The controller may be configured capable of executing: vehicle-speed-based control including shifting the output command value when a vehicle speed falls below a predetermined vehicle speed threshold value; and monitoring control including: measuring an abnormality duration time during which a rotational speed of the pump is deviating from a predetermined allowable range; and outputting a notification signal notifying the abnormality of the pump when the measured abnormality duration time exceeds a predetermined time threshold value. While the controller is measuring the abnormality duration time in the monitoring control, the controller may inhibit the vehicle-speed-based control.

A cooling apparatus may be configured to cool a device mounted in a vehicle. The cooling apparatus may include: a pump configured to circulate a refrigerant between the device and a radiator, and a controller configured to provide an output command value to the pump, and to monitor occurrence of abnormality of the pump. The controller may be configured capable of executing: vehicle-speed-based control including shifting the output command value when a vehicle speed falls below a predetermined vehicle speed threshold value; and monitoring control including: measuring an abnormality duration time during which a rotational speed of the pump is deviating from a predetermined allowable range; and outputting a notification signal notifying the abnormality of the pump when the measured abnormality duration time exceeds a predetermined time threshold value. While the controller is measuring the abnormality duration time in the monitoring control, the controller may inhibit the vehicle-speed-based control.

A pump is provided with a pump housing defining a volute chamber positioned between a central inlet and an impeller face, with the housing defining a recess intersecting the face and surrounding an aperture, and the housing defining sequentially first and second ramps, a wall section, and a protrusion extending into the recess. An impeller is positioned within the chamber adjacent to the face, with the impeller connected to a drive shaft extending through the aperture. A method is provided for cooling a drive shaft sealing member by controlling fluid flow through the pump.

A method for coolant pump flow rationalization using coolant pump parameters includes calculating a first pump coolant flow based on a coolant input pressure sensor signal and the coolant pump speed. Further, the method includes calculating a second pump coolant flow based on coolant pump current and coolant pump speed when the first pump coolant flow is greater than a predetermined threshold; and comparing the first pump coolant flow with the second pump coolant flow to rationalize the coolant pressure sensor signal.

A method for coolant pump flow rationalization using coolant pump parameters includes calculating a first pump coolant flow based on a coolant input pressure sensor signal and the coolant pump speed. Further, the method includes calculating a second pump coolant flow based on coolant pump current and coolant pump speed when the first pump coolant flow is greater than a predetermined threshold; and comparing the first pump coolant flow with the second pump coolant flow to rationalize the coolant pressure sensor signal.

A cooling system includes a cooling device and an electronic control device for controlling the cooling device. The cooling device has a rotating component for delivering cooling medium and a drive source for controlling the rotating component. The electronic control device stores diagnosis reference information, which indicates an actual rotation speed acceptable range when an actual rotation speed of the drive source is apart from an instructed rotation speed of the drive source. The actual rotation speed acceptable range is an acceptable range of the actual rotation speed. The acceptable range changes according to the instructed rotation speed and a voltage value applied to the drive source. The electronic control device obtains the acceptable range based on the diagnosis reference information to determine whether the cooling device is in a normal state.