Abstract: A method includes operating an engine system including a plurality of cylinders, a plurality of fuel injectors configured to provide fuel the plurality of cylinders, a compression braking system configured to selectably brake at least a first set of the plurality of cylinders, and an exhaust aftertreatment system including at least one catalyst. The method includes determining a condition for brake-fuel operation and, in response to the act of determining, operating the engine in a brake-fuel mode wherein the compression brake is actuated to provide compression braking of the first set of the plurality of cylinders and a second set of the plurality of cylinders receives and combust fuel provided from respective ones of the plurality of fuel injectors.

Abstract: An engine control system for protecting a turbocharger of an internal combustion engine from an overspeed condition occurring as a result of a failure of the turbocharger wastegate device. In one embodiment of the invention, sensors provide signals for engine speed, ambient pressure and boost pressure between the turbocharger and the engine intake. Correction factors are added to the boost pressure and ambient pressure signals, and a turbocharger pressure ratio is calculated from these signals. A reduced fueling table maps turbocharger pressure ratio and engine speed to reduced fueling signal values. An engine control computer utilizes a nominal fueling table that maps engine speed and boost pressure to nominal fueling signal values. The control computer also includes a decision module that selects the lesser of the nominal fueling signal values and the reduced fueling signal values and provides the selected value to the engine fueling system.