Abstract: A system and method for controlling a temperature of an exhaust gas at an inlet of a selective catalytic reduction system during at least certain low air density conditions. The system may detect an air density value upstream of an internal combustion engine of an engine system, such as, for example, at an inlet of a compressor. Using the detected air density, one of a plurality of relationships between an engine speed and an outputted engine power, as a function of the detected air density value, may be selected for use in determining what combination of engine speed(s) and/or engine power(s) will produce an exhaust gas that is within a target exhaust gas temperature. Using the selected relationship, at least one of the engine speed and the engine power may be adjusted to at least assist in attaining the target exhaust gas temperature.

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.