Apparatus, Method, and System for Diagnosing Reductant Delivery Performance

摘要

An exhaust gas treatment system for an internal combustion engine may have a reductant delivery system with a controller that performs period diagnostics to determine whether there is a blockage in the reductant delivery system. The diagnostic procedure may include sampling first and second pressures at first and second operating conditions, respectively, and then comparing the first pressure differential between the first and second pressures with one or more threshold pressure differentials to determine whether system components such as a dosing line and an injector are at least partially blocked. If such a test is not conclusive, it may be repeated at a third and fourth operating conditions to provide a second pressure differential. The offset between the first and second pressure differentials may also be used to help diagnose where a blockage in the system resides.

主权项

1. An apparatus for diagnosing a reductant delivery system comprising a reductant pump, the apparatus comprising:
a control module that operates the reductant pump to urge the reductant to flow through the reductant delivery system at a first operating condition and to urge the reductant to flow through the reductant delivery system at a second operating condition different from the first operating condition; a sampling module that samples a first pressure of reductant at the first operating condition and a second pressure of reductant at the second operating condition; a calculation module that calculates a first pressure differential between the first and second pressures; and a comparison module that compares the first pressure differential with a first threshold pressure differential to determine whether the reductant delivery system is operating properly.