Patent ID: 6837226
Filing Date: 2005-01-04
Classification: F02B,F02M

Abstract:
1. A system for diagnosing EGR valve-related failure conditions, comprising: an EGR valve having a valve inlet in fluid communications with an exhaust manifold of an internal combustion engine and a valve outlet in fluid communications with an intake manifold of said engine, said EGR valve responsive to a valve command to control exhaust gas flow therethrough; an EGR valve position sensor producing an EGR valve position signal indicative of EGR valve position; and an engine controller producing said valve command, said engine controller responsive to said valve position signal to determine a final valve position after a time delay following said valve command commanding said EGR valve from one of a fully closed and a fully open position to one of a fully open and a fully closed position, said engine controller logging an EGR valve response time fault if a difference between said final valve position and an expected valve position is greater than a position threshold.