Patent ID: 6354269
Filing Date: 2002-03-12
Classification: F01N,F02B,F02D,F02M,Y02T

Abstract:
A diagnostic system for diagnosing normality of control of an engine which is equipped with a fuel injector for supplying fuel into a combustion chamber, exhaust gas control means for controlling a change in composition of exhaust gas from said engine so as to cause a change in HC concentration of said exhaust gas according to engine operating conditions and an exhaust gas recirculation system for recirculating partly exhaust gas into an intake system of said engine, said diagnostic system comprising:output detecting means for detecting engine output of said engine; and diagnostic means for making a diagnosis of abnormality of said control of said change in composition of said exhaust gas when said engine output does not cause a predetermined change meeting said change in HC concentration of said recirculated exhaust gas after said change in composition of said exhaust gas.