Patent ID: 7921706
Filing Date: 2011-04-12
Classification: F02D,G01M,G01N,Y02A,Y02T

Abstract:
1. An NOx sensor diagnostic device for an internal combustion engine, comprising: an NOx sensor disposed in an exhaust passage of the engine; an output value obtaining means for obtaining an output value of the NOx sensor; a spray characteristics changing means for changing spray characteristics for a specific cylinder of a plurality of cylinders of the engine; and a diagnostic means for diagnosing abnormality of the NOx sensor, based on the output value of the NOx sensor that is changed as a result of the change of the spray characteristics for the specific cylinder by the spray characteristics changing means, wherein: the diagnostic means diagnoses the abnormality of the NOx sensor based also on a response time for the change of the output value of the NOx sensor in response to the change of the spray characteristics for the specific cylinder; and the response time is one of: