Abstract: A method of operating an engine assembly is provided. The engine assembly comprises an engine and a turbocharger assembly, wherein a control parameter of the turbocharger assembly is controllable in order to control a level of boost provided by the turbocharger assembly. The method comprises determining a desirable pressure limit of exhaust gases upstream of a turbine of the turbocharger assembly, predicting a desirable limit value of the control parameter to be applied to the turbocharger assembly in order to achieve the desirable pressure limit, determining an error in the desirable limit value of the control parameter, adjusting the desirable limit value of the control parameter based on the error, and controlling the operation of the turbocharger assembly such that the adjusted limit value is not exceeded.

Abstract: A method of operating an engine assembly is provided. The engine assembly comprises an engine and a turbocharger assembly, wherein a control parameter of the turbocharger assembly is controllable in order to control a level of boost provided by the turbocharger assembly. The method comprises determining a desirable pressure limit of exhaust gases upstream of a turbine of the turbocharger assembly, predicting a desirable limit value of the control parameter to be applied to the turbocharger assembly in order to achieve the desirable pressure limit, determining an error in the desirable limit value of the control parameter, adjusting the desirable limit value of the control parameter based on the error, and controlling the operation of the turbocharger assembly such that the adjusted limit value is not exceeded.

Abstract: A method for operating an internal combustion engine Exhaust Gas Recirculation (EGR) system that includes producing an EGR valve position signal to decrease the amount of exhaust gas passed to the EGR cooler when a processor determines the EGR cooler efficiency is less than the predetermined level and producing an EGR coolant valve position signal to decrease the amount of coolant passed to the EGR cooler when such processor determines the EGR cooler efficiency is less than the predetermined level. The processor produced EGR valve and the EGR coolant valve position signals result in regeneration within the cooler, returning the effectiveness of the cooler to a near “clean” condition.

Abstract: A method for operating an internal combustion engine Exhaust Gas Recirculation (EGR) system that includes producing an EGR valve position signal to decrease the amount of exhaust gas passed to the EGR cooler when a processor determines the EGR cooler efficiency is less than the predetermined level and producing an EGR coolant valve position signal to decrease the amount of coolant passed to the EGR cooler when such processor determines the EGR cooler efficiency is less than the predetermined level. The processor produced EGR valve and the EGR coolant valve position signals result in regeneration within the cooler, returning the effectiveness of the cooler to a near “clean” condition.

Abstract: A method for controlling an engine having an intake manifold and an exhaust manifold, where an exhaust gas recirculation path with a valve is provided between said intake and exhaust manifold, and the engine has a turbocharger; the method comprising during at least one decreased engine output condition, increasing opening of the exhaust gas recirculation valve and adjusting exhaust expansion through a turbine of the turbocharger to decrease expansion through the turbocharger and thereby reduce a likelihood of turbocharger surge.