Patent ID: 9399942
Filing Date: 2016-07-26
CPC Classification: F01N,G01M,Y02T

Claim Text:
1. A method for performing diagnostics of reductant delivery performance of a NOx conversion system, the method comprising the steps of: providing an outlet pressure sensor at a reductant outlet of a reductant delivery system; providing a virtual pressure sensor in an exhaust stream at a location where the reductant is injected into the exhaust stream; calculating a downstream reductant flow rate using at least one of the outlet pressure sensor and the virtual pressure sensor; calculating an upstream reductant flow rate within the reductant delivery system using at least one of a temperature sensor, a pressure sensor and a control valve; comparing the calculated downstream reductant flow rate with the calculated upstream reductant flow rate; and conducting diagnostics based on the results from the comparison of the calculated downstream reductant flow rate with the calculated upstream reductant flow rate.