A thermostat monitoring method includes measuring an engine coolant temperature with an engine coolant temperature sensor a predetermined amount of time after engine startup, comparing, with a controller, the engine coolant temperature to determine whether the engine coolant temperature has met a predetermined threshold, when the engine coolant temperature has met the predetermined threshold, measuring a plurality of engine coolant temperatures with the engine coolant temperature sensor, comparing with the controller each of the plurality of engine coolant temperatures with a corresponding predetermined temperature model, and increasing a passing index with the controller for each of the plurality of engine coolant temperatures that is greater than the corresponding predetermined temperature model or reducing the passing index for each of the plurality of engine coolant temperatures that is less than the corresponding predetermined temperature model.

Systems and methods for determining an idle, recommended cool-down period (RCDP) for a prime mover of a grounds maintenance vehicle. Delaying engine shutdown until after expiration of the RCDP allows engine components to adequately cool. In some embodiments, systems and methods may provide a quantitative indication of the time remaining in the RCDP, while other embodiments may notify an operator that a re-start of the engine is necessary to continue cool-down.

A control method for a cooling system includes determining, by the controller, whether the output signal of the ambient temperature sensor satisfies a predetermined an ambient low temperature driving condition, determining, by the controller, whether the output signal of the first coolant temperature sensor satisfies a predetermined first low temperature driving condition when the output signal of the ambient temperature sensor satisfies the predetermined the ambient low temperature driving condition and controlling, by the controller, the operation of the coolant control valve unit to open the first coolant passage and the third coolant passage and to close the second coolant passage when the output signal of the first coolant temperature sensor satisfies the predetermined first low temperature driving condition.

A thermostat monitoring method includes measuring an engine coolant temperature with an engine coolant temperature sensor a predetermined amount of time after engine startup, determining with a controller one of four zones to determine whether a thermostat will pass or fail, based on the one of four zones determined, accumulate with the controller one a pass index or a failing index, when the pass index reaches a first threshold, reporting a pass with the controller, and when the failing index reaches a second threshold, reporting a fail with the controller.

A method for controlling a water pump for a vehicle includes: determining whether an engine is on; measuring a coolant temperature of the engine and an RPM of the engine when the engine is determined to be operated; determining whether the measured coolant temperature is equal to or greater than a predetermined coolant temperature; determining an RPM of a water pump, which adjusts a coolant flow rate, from the measured coolant temperature and the measured RPM of the engine, when the measured coolant temperature is determined to be equal to or greater than the predetermined coolant temperature; and controlling the water pump such that the water pump is operated according to the determined RPM of the water pump.

A controller for a motor vehicle cooling system thermostatic valve assembly, the assembly having a radiator bypass coolant flow inlet, a radiator coolant flow inlet and a coolant outlet, the assembly being configured to allow flow of coolant from the bypass coolant flow inlet to the coolant outlet and from the radiator coolant flow inlet to the coolant outlet, the assembly comprising means for controlling a flow rate of fluid from the radiator coolant flow inlet to the coolant outlet, the controller being configured to receive an ambient temperature signal indicative of an ambient air temperature, the controller being configured to control flow of coolant from the radiator coolant flow inlet to the coolant outlet in dependence at least in part on the ambient temperature signal.

Methods and systems for managing a monitoring of an engine cooling system. A transient condition associated with an engine system is identified. A determination is made as to whether the transient condition is a delay condition based on whether the transient condition exceeds a transient threshold. A determination is made, in response to a determination that the transient condition is not the delay condition, as to whether a period of time that has passed since a previously identified delay condition meets a time threshold. Monitoring of a health of the engine cooling system is enabled in response to a determination that the period of time meets the time threshold.

A thermostat misdiagnosis prevention method applied to an engine system of the present disclosure applies high speed/high load and low speed/low load, which are divided by a vehicle speed and an engine output detected from the engine system at an engine warm-up temperature of engine coolant, as monitoring conditions of a thermostat, and determines thermostat fail by primarily determining the thermostat fail with the engine coolant temperature of the engine coolant temperature and the outside air temperature detected from the engine system, then confirming a delay time with respect to the outside air temperature, and secondarily determining the thermostat fail with the engine coolant temperature in a monitoring ECU, thereby corresponding to the enhanced OBD together with preventing the misdiagnosis of the thermostat by the fail-safe according to the primary and secondary determinations.

A heat radiation amount from the cooling water in the radiator is adjusted so that the temperature of the cooling water is less than a prescribed temperature that is a temperature higher than the threshold value if a load exerted on the internal combustion engine is not less than a predetermined load, while the heat radiation amount from the cooling water in the radiator is adjusted so that the heat radiation amount from the cooling water in the radiator is increased if the load exerted on the internal combustion engine is less than the predetermined load as compared with if the load exerted on the internal combustion engine is not less than the predetermined load.

A method to operate a combustion machine having at least an internal combustion engine, a fresh gas line and a cooling system comprising an ambient heat exchanger. A compressor, which can especially be part of an exhaust gas turbocharger, is integrated into the fresh gas line, and an intercooler is integrated between the compressor and the internal combustion engine and also into the cooling system. In case of an increase in the load demand that is made of the operation of the internal combustion engine, the temperature of the coolant flowing in the cooling system and entering the intercooler is lowered. As a result, the cooling output of the intercooler is increased and consequently, the temperature of the fresh gas (charge air) entering the internal combustion engine is also lowered. The associated increase in the density of the charge air leads to an increased filling of the combustion chambers of the internal combustion engine which, especially in conjunction with the use of an exhaust gas turbocharger, has a positive effect on the build-up of the charge pressure and thus on the dynamic operating behavior of the internal combustion engine as well as on the start-up and elasticity output of a motor vehicle.