Abstract: An engine controller determines the cost of operating a combustion engine and the cost of operating an emissions after-treatment device. Accordingly, the engine controller adjusts parameters for operation of the engine and the after-treatment device to ensure cost-effective use of the engine and the after-treatment device while complying with exhaust emissions requirements. In particular, the engine controller receives the price of fuel consumed by the engine and the price of reductant used by the after-treatment device to determine the respective cost of operation. Specifically, the fuel is diesel fuel used in a diesel engine; the reductant is urea use in a urea-based Selective Catalytic Reduction (SCR) system; and the regulated exhaust emissions is nitrogen oxide (NOx) emissions. The engine operating parameters may include cooled exhaust gas recirculation airflow, fuel injection timing, fuel injection pressure, and air-to-fuel ratio.

Abstract: An engine controller determines the cost of operating a combustion engine and the cost of operating an emissions after-treatment device. Accordingly, the engine controller adjusts parameters for operation of the engine and the after-treatment device to ensure cost-effective use of the engine and the after-treatment device while complying with exhaust emissions requirements. In particular, the engine controller receives the price of fuel consumed by the engine and the price of reductant used by the after-treatment device to determine the respective cost of operation. Specifically, the fuel is diesel fuel used in a diesel engine; the reductant is urea use in a urea-based Selective Catalytic Reduction (SCR) system; and the regulated exhaust emissions is nitrogen oxide (NOx) emissions. The engine operating parameters may include cooled exhaust gas recirculation airflow, fuel injection timing, fuel injection pressure, and air-to-fuel ratio.

Abstract: A system for determining a NOx conversion efficiency of an exhaust gas aftertreatment component comprises means for determining an operating temperature of the exhaust gas aftertreatment component, and a control circuit. The control circuit includes a memory having instructions stored therein that are executable by the control circuit to determine a time duration that the operating temperature of the exhaust gas aftertreatment component is above a predefined temperature, and to determine the NOx conversion efficiency of the exhaust gas aftertreatment component as a function of the time duration.

Abstract: A system for determining a NOx conversion efficiency of an exhaust gas aftertreatment component comprises means for determining an operating temperature of the exhaust gas aftertreatment component, and a control circuit. The control circuit includes a memory having instructions stored therein that are executable by the control circuit to determine a time duration that the operating temperature of the exhaust gas aftertreatment component is above a predefined temperature, and to determine the NOx conversion efficiency of the exhaust gas aftertreatment component as a function of the time duration.

Abstract: An engine controller determines the cost of operating a combustion engine and the cost of operating an emissions after-treatment device. Accordingly, the engine controller adjusts parameters for operation of the engine and the after-treatment device to ensure cost-effective use of the engine and the after-treatment device while complying with exhaust emissions requirements. In particular, the engine controller receives the price of fuel consumed by the engine and the price of reductant used by the after-treatment device to determine the respective cost of operation. Specifically, the fuel is diesel fuel used in a diesel engine; the reductant is urea use in a urea-based Selective Catalytic Reduction (SCR) system; and the regulated exhaust emissions is nitrogen oxide (NOx) emissions. The engine operating parameters may include cooled exhaust gas recirculation airflow, fuel injection timing, fuel injection pressure, and air-to-fuel ratio.

Abstract: A system for providing accurately time stamped vehicle operational messages following a real-time clock reset includes a vehicle control computer having a processor, a memory and a real-time clock powered by a constant power source. The processor is operable to store a current value of the real-time clock in memory at engine shut down and to determine whether a clock reset event occurred since the previous engine operational cycle by testing a clock error flag in memory. If such a clock reset event occurred, the processor is operable to reset the real-time clock at the clock value stored at engine shut down and store this value in an error buffer of the memory. Upon establishment of communications with a time correction device having a master real-time clock, the processor is operable to determine whether the error buffer contains any clock values therein.