A hybrid electric vehicle includes: an engine including a turbocharger and an intercooler that cools intake air; a motor; an inverter for driving the motor; a cooling device for cooling the inverter and the intake air by circulating a cooling medium by a circulation pump in a circulation path including a cooling flow path for cooling the inverter and a cooling flow path for the intercooler as a flow path; and a control device for controlling the cooling device. The control device permits forced drive of the circulation pump from an outside when predetermined conditions including a condition that a vehicle speed is equal to or lower than a predetermined vehicle speed and a condition that a vehicle system is turned off are satisfied.

An apparatus includes two pumps and a circuit-changing valve connected to two cooling circuits, with the valve being controlled by a pressure differential created by the pumps. This simplifies controls, reduces components of the pumping system, and also provides a backup pump for each system. The valve's spool is controlled so that when the first pump is started before the second pump (or it generates a higher fluid pressure), the valve causes the two pumps to be connected in a serial arrangement with fluid being pumped through the first circuit and then through the second circuit. But when the second pump is started before the first pump, the valve causes the two pumps to be connected in a parallel arrangement so that the first pump moves fluid only through the first circuit, and the second pump moves fluid only through the second circuit. The valve includes an anti-dithering device.

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 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.

An anomaly diagnosing apparatus is adapted for a cooling device in an internal combustion engine. The apparatus is configured to execute an enlarging process, a rate calculating process, and an anomaly determining process. The enlarging process includes enlarging the cross-sectional area of the flow passage between an inner channel and an outer channel in the cooling device. The rate calculating process includes calculating a reference rate for a rate of rise of temperature of cooling water. The anomaly determining process includes determining that an anomaly is present in the check valve if a rate of rise of a detection value of cooling water temperature is smaller than the reference rate. The rate calculating process includes calculating the reference rate such that the reference rate has a smaller value in a case where the enlarging process is executed than in a case where the enlarging process is not executed.

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.

The invention of the present application relates to a control device and a control method for a cooling device. A cooling device includes a first cooling water passage of a cylinder head, a second cooling water passage of a cylinder block, a control valve that changes a ratio between a flow rate of the first cooling water passage and a flow rate of the second cooling water passage, and a water pump. Then, the control device controls the control valve so that a ratio of the flow rate of the first cooling water passage increases when a cooling water circulation flow rate is insufficient due to failure of the water pump. Accordingly, it is possible to suppress damage of an engine body while suppressing deterioration in traveling performance of a vehicle when failure occurs in the water pump.

An apparatus includes two pumps and a circuit-changing valve connected to two cooling circuits, with the valve being controlled by a pressure differential created by the pumps. This simplifies controls, reduces components of the pumping system, and also provides a backup pump for each system. The valve's spool is controlled so that when the first pump is started before the second pump (or it generates a higher fluid pressure), the valve causes the two pumps to be connected in a serial arrangement with fluid being pumped through the first circuit and then through the second circuit. But when the second pump is started before the first pump, the valve causes the two pumps to be connected in a parallel arrangement so that the first pump moves fluid only through the first circuit, and the second pump moves fluid only through the second circuit. The valve includes an anti-dithering device.

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.