A control method for an engine coolant valve includes: monitoring an engine driving condition and an engine driving environment; predicting, by a controller, degradation of an engine coolant based on the engine driving condition and the engine driving environment by a controller; changing, by the controller, an opening of an integrated flow control valve when the engine coolant is predicted to be degraded; and generating, by the controller, a coolant exchange alarm when the engine coolant is predicted to be out of a control range and degraded.

A control method for an engine coolant valve includes: monitoring an engine driving condition and an engine driving environment; predicting, by a controller, degradation of an engine coolant based on the engine driving condition and the engine driving environment by a controller; changing, by the controller, an opening of an integrated flow control valve when the engine coolant is predicted to be degraded; and generating, by the controller, a coolant exchange alarm when the engine coolant is predicted to be out of a control range and degraded.

An engine cooling device includes a heater circulation passage including an exhaust-side channel and a heater channel, the exhaust-side channel extending through an exhaust port-side portion of a cylinder head, the heater channel extending through a heater core; an auxiliary device circulation passage including a main channel and an auxiliary device channel, the main channel extending through a portion of the cylinder head other than the exhaust port-side portion, the auxiliary device channel extending through an auxiliary device; a temperature detecting portion configured to detect a temperature of an engine; and a channel switching valve configured to perform connection between the main channel and the auxiliary device channel and connection between the heater circulation passage and the auxiliary device circulation passage depending on the detected temperature falling within one of three temperature ranges.

A coolant circuit for an internal combustion engine includes: a coolant pump; at least one coolant line; a radiator; and a coolant cavity delimited in the internal combustion engine. The coolant pump, the coolant line, the radiator and the coolant cavity are filled with a coolant. One or more sensors, configured to monitor the coolant concentration, are fixedly and permanently arranged in and/or on the coolant circuit.

A coolant circuit for an internal combustion engine includes: a coolant pump; at least one coolant line; a radiator; and a coolant cavity delimited in the internal combustion engine. The coolant pump, the coolant line, the radiator and the coolant cavity are filled with a coolant. One or more sensors, configured to monitor the coolant concentration, are fixedly and permanently arranged in and/or on the coolant circuit.

A control method for a vehicle includes determining whether an internal combustion engine is overheated based on driving information of the vehicle and cooling information of a passenger compartment while the vehicle is driving and an HVAC system is operating in a cooling mode, and controlling an alternator or an actuator of a switching door to reduce a cooling capacity provided by the HVAC system when it is determined that the internal combustion engine is overheated.

A refrigerant control valve apparatus includes a valve body provided with a main control valve controlling the refrigerant sent to a discharge port and a temperature sensing control valve controlling supply and discharge of the refrigerant to a temperature sensing chamber. A fail-safe mechanism is provided which supplies the refrigerant to the discharge port in a case where the temperature of the refrigerant exceeds a set value. The temperature sensing control valve is set in an open posture in a case where the main control valve is in a closed posture that closes the discharge port and the temperature sensing control valve is set in a closed posture in a case where the main control valve is in an open posture that opens the discharge port.

An engine coolant temperature sensor configured to earth through the engine coolant such that an alarm will trigger when coolant is absent.

An engine coolant temperature sensor configured to earth through the engine coolant such that an alarm will trigger when coolant is absent.

An engine ECU is provided with an abnormality-diagnosis unit performing an abnormality diagnosis of an Air-Con ECU, and a monitoring IC monitoring the abnormality-diagnosis unit. The abnormality-diagnosis unit determines whether the output signal of the Air-Con ECU is normal based on the specified criterion value, so that the abnormality diagnosis of the Air-Con ECU is performed. The monitoring IC determines whether a criterion value is normal, which is used during the abnormality diagnosis of the Air-Con ECU. The abnormality-diagnosis unit performs an abnormality diagnosis of the monitoring IC. When the monitoring IC determines that the criterion value is abnormal or the abnormality-diagnosis unit determines that the monitoring IC is abnormal, the abnormality diagnosis of the Air-Con ECU is prohibited and a specified operation for abnormality is performed.