Patent ID: 6848434
Filing Date: 2005-02-01
Classification: F02M

Abstract:
1. System for diagnosing operation of an exhaust gas recirculation (EGR) cooler, comprising: an engine having an intake manifold, an exhaust manifold and an EGR conduit fluidly coupled between said intake and exhaust manifolds, said engine including a cooling system having a coolant fluid circulating therethrough to cool said engine; an EGR cooler disposed in-line with said EGR conduit such that exhaust gas flowing through said EGR conduit also flows through said EGR cooler, said EGR cooler coupled to said cooling system such that said coolant fluid circulates through said EGR cooler to cool exhaust gas flowing therethrough: means for determining a temperature of exhaust gas produced by said engine; means for determining a temperature of exhaust gas exiting an exhaust gas outlet of said EGR cooler; means for determining a temperature of said coolant fluid circulating through said engine cooling system and said EGR cooler; means for determining a flow rate of exhaust gas through said EGR conduit; and means for diagnosing operation said EGR cooler as a function of said temperature of exhaust gas produced by said engine, said temperature of exhaust gas exiting said EGR cooler, said temperature of said coolant fluid and said flow rate of exhaust gas through said EGR conduit.