Abstract: An engine system having a reductant delivery and storage system is described. In one example, a physical condition associated with a reductant storage device is correlated with a characteristic of a fluid stored in the reductant storage device to determine the availability and make-up of the stored fluid. In response, engine operation may be adjusted.

Abstract: An engine system having a reductant delivery and storage system is described. In one example, a physical condition associated with a reductant storage device is correlated with a characteristic of a fluid stored in the reductant storage device to determine the availability and make-up of the stored fluid. In response, engine operation may be adjusted.

Abstract: A engine system having a reductant delivery and storage system is described. In one example, a physical condition associated with a reductant storage device is correlated with a characteristic of a fluid stored in the reductant storage device to determine the availability and make-up of the stored fluid. In response, engine operation may be adjusted.

Abstract: A method of operating an internal combustion engine having a reductant delivery and storage system in an emission control system, comprising coordinating a physical condition associated with a reductant storage device, wherein the physical condition may correspond to a measure of liquid stored in the reductant storage device, with a characteristic of a fluid stored in the reductant storage device to determine the availability and make-up of the stored fluid, wherein at least one of the physical condition and the property of the stored fluid is determined by a plurality of sensors; and adjusting engine operation based on said coordinating the condition associated with the reductant storage device with the property of the stored fluid.