A system and method for diagnosing a component failure in an internal combustion engine having an exhaust gas recirculation system and a variable geometry turbocharger for diverting exhaust gas from an engine exhaust to an engine intake include determining whether the engine is operating in boost control...http://www.google.com/patents/US6457461?utm_source=gb-gplus-sharePatent US6457461 - EGR and VGT system diagnostics and control
