Method and system for reductant injector degradation

摘要

Various systems and methods for detecting exhaust reductant injector degradation based on an exhaust NOx sensor are disclosed. In one example, degradation of the reductant injector is indicated when an actual NOx sensor output differs from an expected NOx sensor output by more than a threshold amount under engine off conditions.

主权项

1. A method for controlling an engine via an electronic controller, comprising:
shutting down the engine to rest and not spinning; generating an output from a feedgas exhaust NOx sensor coupled to an exhaust passage upstream of an exhaust reduction catalyst; and indicating degradation of an exhaust reductant injector based on the output of the feedgas exhaust NOx sensor.