Abstract: Systems and methods are disclosed for determining a temperature of a coolant in a cooling system for an engine and diagnosing a thermostat in the engine responsive to the determined temperature. A system includes a liquid cooling system including a thermostat, the liquid cooling system structured to circulate a coolant, and a controller coupled to the liquid cooling system and the EGR system. The controller is structured to: receive engine heat data indicative of a first amount of heat introduced into an engine; receive heat loss data indicative of an amount of heat loss experienced by the coolant; determine a temperature of the coolant based on the first amount of heat and the amount of heat loss; compare the determined temperature of the coolant to a sensed temperature of the coolant; and determine a status of the thermostat responsive to the comparison.

Abstract: Systems and methods are disclosed for determining a temperature of a coolant in a cooling system for an engine and diagnosing a thermostat in the engine responsive to the determined temperature. A system includes a liquid cooling system including a thermostat, the liquid cooling system structured to circulate a coolant, and a controller coupled to the liquid cooling system and the EGR system. The controller is structured to: receive engine heat data indicative of a first amount of heat introduced into an engine; receive heat loss data indicative of an amount of heat loss experienced by the coolant; determine a temperature of the coolant based on the first amount of heat and the amount of heat loss; compare the determined temperature of the coolant to a sensed temperature of the coolant; and determine a status of the thermostat responsive to the comparison.

Abstract: Systems and methods are disclosed for determining a temperature of a coolant in a cooling system for an engine and diagnosing a thermostat in the engine responsive to the determined temperature. The system and method includes interpreting engine heat data indicative of a first amount of heat introduced into the internal combustion engine; interpreting exhaust gas recirculation (EGR) heat data indicative of a second amount of heat introduced into the internal combustion engine via the amount of exhaust gas provided to the intake manifold; interpreting heat loss data indicative of an amount of heat loss experienced by the coolant; determining a temperature of the coolant based on the first amount of heat, the second amount of heat, and the amount of heat loss; comparing the determined temperature of the coolant to a sensed temperature of the coolant; and determining a status of the thermostat responsive to the comparison.

Abstract: Systems and methods are disclosed for determining a temperature of a coolant in a cooling system for an engine and diagnosing a thermostat in the engine responsive to the determined temperature. The system and method includes interpreting engine heat data indicative of a first amount of heat introduced into the internal combustion engine; interpreting exhaust gas recirculation (EGR) heat data indicative of a second amount of heat introduced into the internal combustion engine via the amount of exhaust gas provided to the intake manifold; interpreting heat loss data indicative of an amount of heat loss experienced by the coolant; determining a temperature of the coolant based on the first amount of heat, the second amount of heat, and the amount of heat loss; comparing the determined temperature of the coolant to a sensed temperature of the coolant; and determining a status of the thermostat responsive to the comparison.

Abstract: One embodiment is a unique strategy for evaluating performance of a component of an internal combustion engine. More particularly, in one non-limiting form a method includes operating a component, such as a heating component, and measuring a first characteristic related to its operation. The method also includes operating an engine accessory and measuring a second characteristic related to its operation, and determining performance of the component by relating the first and second characteristics to one another. In one aspect, relating the first and second characteristics to one another provides a first value which is compared to a predetermined value, and performance of the component is determined from this comparison. Other embodiments include unique methods, systems, and apparatus for evaluating or monitoring the performance of a component of an internal combustion engine, and/or for performing a procedure for starting the internal combustion engine.

Abstract: One embodiment is a unique strategy for evaluating performance of a component of an internal combustion engine. More particularly, in one non-limiting form a method includes operating a component, such as a heating component, and measuring a first characteristic related to its operation. The method also includes operating an engine accessory and measuring a second characteristic related to its operation, and determining performance of the component by relating the first and second characteristics to one another. In one aspect, relating the first and second characteristics to one another provides a first value which is compared to a predetermined value, and performance of the component is determined from this comparison. Other embodiments include unique methods, systems, and apparatus for evaluating or monitoring the performance of a component of an internal combustion engine, and/or for performing a procedure for starting the internal combustion engine.