Abstract: An aftertreatment system is disclosed for use with a combustion engine. The aftertreatment system may have at least one exhaust passage, and a plurality of dosing circuits configured to inject reductant into the at least one exhaust passage. The aftertreatment system may also have a controller in communication with each of the plurality of dosing circuits. The controller may be configured to determine a failure of a first of the plurality of dosing circuits, and to selectively adjust operation of a second of the plurality of dosing circuits based on the failure.

Abstract: Methods and apparatus are provided for testing a fuel pump in a fuel supply system on a IC fuel injected engine, the pump having a pumping element for supplying fuel injectors via a fuel rail. The method includes providing a pump element pumping event; disabling overlapping injectors during a test-period that includes the pumping event; measuring pressure in the rail at least two engine crank angles surrounding the pumping event during the test period; and determining a fuel delivery rate value for the pump based on the measured rail pressures. Methods and apparatus also are provided for determining quantitative leakage rate in the fuel supply system of a fuel injected IC engine, the fuel system including a fuel pump with one or more pumping elements supplying injectors via a fuel rail.

Abstract: Methods and apparatus are provided for testing a fuel pump in a fuel supply system on a IC fuel injected engine, the pump having a pumping element for supplying fuel injectors via a fuel rail. The method includes providing a pump element pumping event; disabling overlapping injectors during a test-period that includes the pumping event; measuring pressure in the rail at at least two engine crank angles surrounding the pumping event during the test period; and determining a fuel delivery rate value for the pump based on the measured rail pressures. Methods and apparatus also are provided for determining quantitative leakage rate in the fuel supply system of a fuel injected IC engine, the fuel system including a fuel pump with one or more pumping elements supplying injectors via a fuel rail.