A method of diagnosing a leak in a coolant system of an automobile includes repeatedly measuring the coolant level within the coolant system at a pre-determined time interval, calculating a short term leak rate, wherein the short term leak rate is the rate of coolant leakage over a first pre-determined length of time, calculating a long term leak rate, wherein the long term leak rate is the rate of coolant leakage over a second pre-determined length of time, further wherein the second pre-determined length of time is longer than the first pre-determined length of time, identifying a coolant system leakage state based on a current coolant level within the coolant system, the short term leak rate, and the long term leak rate, and providing notification of the coolant system leakage state to an operator of the vehicle.

A method for ascertaining a control-caused behavior of a valve installed in a vehicle for adjusting a flow of a medium. Operating a pump, which has an electric motor and at least one pump element for conveying the medium, so that the medium is conveyed by the pump in that the pump element is driven by means of the electric motor. Controlling the valve by an electronic computing device of the vehicle. The control of the valve is varied by the electronic computing device. While the medium is conveyed by the pump, and while the control of the valve is varied: sensing at least one parameter characterizing the operation of the pump. Determining the behavior of the valve as a function of the sensed parameter.

An anomaly determination device, an anomaly determination method, and a memory medium for a water pump are provided. An acquisition process acquires an input variable of a map from image data obtained by capturing an outer surface of the water pump. Execution circuitry obtains provisional determination results from maps, respectively. The provisional determination results are respectively obtained by executing the provisional determination processes for output variables output from the maps. A determination finalizing process treats, as a majority of the provisional determination results, a final determination result indicating whether coolant has leaked out of the water pump.

Methods and systems are provided for determining coolant system health. In one example, a method may include predicting degradation in the coolant system based on oscillations of an estimated coolant temperature at an outlet of a radiator. The method may further control an engine based on the estimated coolant temperature.

A method for ascertaining a control-caused behavior of a valve installed in a vehicle for adjusting a flow of a medium. Operating a pump, which has an electric motor and at least one pump element for conveying the medium, so that the medium is conveyed by the pump in that the pump element is driven by means of the electric motor. Controlling the valve by an electronic computing device of the vehicle. The control of the valve is varied by the electronic computing device. While the medium is conveyed by the pump, and while the control of the valve is varied: sensing at least one parameter characterizing the operation of the pump. Determining the behavior of the valve as a function of the sensed parameter.

Upon a valve rotation angle of a flow rate control valve exceeding a radiator-flow-path closed position during changing of the valve rotation angle of the flow rate control valve in an opening direction of a radiator flow path from a closed state of the radiator flow path, a cooling water starts to circulate through the radiator flow path, and an outlet water temperature or an inlet water temperature of an engine starts to drop. The radiator-flow-path closed position is learned as a valve rotation angle of the flow rate control valve immediately before the outlet water temperature or the inlet water temperature starts to drop during changing of the valve rotation angle of the flow rate control valve in the opening direction of the radiator flow path from the closed state of the radiator flow path.

An engine coolant system includes a variable-opening valve having a plurality of tubes in fluid flow communication with an engine block and a radiator. The coolant system also includes an electrically-powered pump arranged to cycle coolant through the radiator and the engine block to regulate an engine temperature. The coolant system further includes a controller programmed to store a baseline relationship between pump speed and pump power draw using a nonlinear scale. The controller is also programmed to detect a steady state operating condition of the pump, and identify an operational relationship between real-time pump speed and a pump power draw. The controller is further programmed to detect a coolant leak based on a deviation between the baseline relationship and the operational relationship.

A thermal management system includes an electric coolant pump, power source, and controller. The pump is in fluid communication with a heat source and a radiator, and has pump sensors for determining a pump voltage, speed, and current. The battery energizes the sensors. The controller receives the voltage, speed, and current from the sensors, determines a performance of the pump across multiple operating regions, calculates a numeric state of health (SOH) quantifying degradation severity for each of a plurality of pump characteristics across the regions, and executes a control action when the calculated numeric SOH for any region is less than a calibrated SOH threshold. The pump characteristics include pump circuit, leaking/clogging, bearing, and motor statuses. A vehicle includes an engine or other heat source, a radiator; and the thermal management system. The controller may execute a prognostic method for the electric coolant pump in the vehicle.

In one aspect, a method for detecting and diagnosing a coolant leak of an engine may include diagnosing a coolant leak of the engine based on a low frequency pressure response of a measured engine coolant pressure. In another aspect, an engine system (e.g., for a vehicle) includes an engine and a coolant system operatively connected to the engine. The coolant system includes a coolant reserve and a coolant pump between the engine and the coolant reserve. The engine system also includes a coolant pressure sensor to measure coolant pressure, and a controller configured to measure an engine coolant pressure and diagnose a coolant leak of the coolant system based on a low frequency pressure response of the measured engine coolant pressure.

Methods and systems are provided for determining coolant system health. In one example, a method may include predicting degradation in the coolant system based on oscillations of an estimated coolant temperature at an outlet of a radiator. The method may further control an engine based on the estimated coolant temperature.