A fail-safe control method for a vehicle cooling system, in which an engine and a vehicle can be properly operated even when a water temperature sensor malfunctions. When only one of two water temperature sensors malfunctions, control may be performed so that an engine and a vehicle can properly operate. When both the two water temperature sensors malfunction, the fail-safe function of the flow rate control valve can be enabled to entirely prevent cooling water from being overheated, thereby improving the reliability of the operation of the vehicle.

A method is provided for operating a cooling system of an internal combustion engine, which cooling system has a controllable rotary slide valve with at least one switched inlet or outlet. The movement of the rotary slide valve into a plurality of switching positions, which each correspond with a cooling system state, is monitored. In accordance with an improper functional state of the rotary slide valve and a current switching position of the rotary slide valve, an operating state of the internal combustion engine is changed to an emergency operation state. A protection system in the cooling system carries out the method and includes a thermal management system, which receives and processes coolant temperatures, and a control unit of a controllable rotary slide valve having a position detector, which can detect a current switching position of the switchable rotary slide valve, wherein the thermal management system is connected to the control unit of the rotary slide valve.

A main valve unit is rotatably provided in a main valve accommodation space connected to a first opening portion. A fail-safe valve unit is provided in a fail-safe valve accommodation space connected to a second opening portion. The main valve unit controls flow rate of cooling water flowing from the first opening portion to a radiator via a main water passage formed in a housing depending on a rotational position thereof. The fail-safe valve unit is closed when temperature of the cooling water is lower than a predetermined value, to thereby block off flow of the cooling water to the radiator. The fail-safe valve unit is opened when the temperature of the cooling water is higher than the predetermined value, to thereby allow the flow of the cooling water to the radiator. Each of the first opening portion and the main valve accommodation space is fluidically separated from the second opening portion and the fail-safe valve accommodation space by a partitioning wall formed in the housing.

A heat exchange module has a restriction protrusion that is provided to protrude between a blade of a cooling fan and a core portion of a heat exchanger and that restricts the blade from approaching the core portion more than a predetermined position. In a state where one side of an outline of a rectangular shaped fan shroud is disposed so as to face an installation surface, the restriction protrusion is provided in a position where the amount of water reaching the cooling fan through the heat exchanger becomes greater than the amount of water at position just below a rotation axis of the cooling fan in a case where at least a portion of the fan shroud is submerged in water.

A valve device with fail-safe mechanism capable of improved production efficiency includes a valve element, a valve element housing, a third communication port provided in the valve element housing, and a fail-safe mechanism. The fail-safe mechanism includes a thermo-element and an element housing that houses the thermo-element. The element housing, has a large-diameter housing, a small-diameter housing portion that accommodates the thermo-element, and a step. A valve element communicating portion communicating with the valve element housing is provided to the small-diameter housing portion. The fail-safe mechanism includes a valve plate member for closing the step and a coil spring that biases the valve plate member. A third adapter provided to the third communication port is provided with a through-hole that enables the large-diameter housing portion and the third communication port to communicate with each other.

An engine-controlling device includes a coolant passage, a radiator, and a control valve. A coolant discharged from a pump circulates through the coolant passage. The radiator cools the coolant. The control valve includes a first valve that adjusts a flow rate of the coolant to be introduced into the radiator and that includes a valve member driven by an electric actuator, a second valve that is arranged in parallel with the first valve and that includes a valve member that is opened in accordance with a pressure or a temperature, and a malfunction-diagnosing unit that detects a valve-stuck malfunction of the first valve. An output of the engine is limited to an output equal to or less than a limiting value determined on a basis of a maximum flow rate of the coolant introduced into the radiator from the second valve when the valve-stuck malfunction of the first valve occurs.

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.

A cooling device includes a first cooling medium circuit for circulating a cooling medium that passes through a main body of an engine to a first heat exchanger, a second cooling medium circuit for circulating a cooling medium that passes through the main body to a second heat exchanger, a control valve that is commonly used in the first and second cooling medium circuits, and a control device. The control valve includes a rotatable rotor, and is configured such that a rotation range of the rotor includes a water stop section in which the circuits are both closed. The control device restricts output power of the engine in a period in which the rotation angle is in the water stop section, when the rotor rotates via the water stop section at an operating time of the control valve.

A cooling system of an internal combustion engine includes a first flow passage supplying a cooling medium of the internal combustion engine to a radiator, a second flow passage branching from the first flow passage by a flow control valve to supply the cooling medium to a first heat exchanging portion, a third flow passage provided separately from the first flow passage to supply the cooling medium to a second heat exchanging portion via an on-off valve and a control portion controlling the on-off valve and the flow control valve based on a temperature of the cooling medium.

A solenoid fluid control valve for controlling fluid flow. The solenoid fluid control valve may comprise a transceiver that receives a signal via a controller area network (CAN) bus, and a micro controller unit that decodes the signal to determine a temperature. The micro controller unit may send a signal to a driver circuit based on the temperature. The driver circuit may send a current through a coil in response to the signal, wherein an armature moves in response to the current through the coil. The movement of the armature may direct a cooling fluid flow.