| 摘要 |
<p>A system and method for diagnosing a failure in an exhaust gas recirculation system (66,68) for diverting exhaust gas from an engine exhaust (58) to an engine intake (69) and a variable geometry turbocharger (52). The system andmethod determining whether an engine (12) is operating in boost control mode or EGR control mode, comparing EGR flow rate to a threshold correspending to the current control mode, generating a fault if the EGR flow rate is outside an acceptable operating range based on the threshold for a first predetermined time period, and operating in boost control mode if the fault persists for a second predetermined time period. The system and method generate an EGR fault if the EGR flow rate is less than the minimum threshold. When operating in the boost control mode, the system and method generate an EGR fault if the EGR mass flow rate exceeds a maximum flow rate and generate a VGT fault if the turbo boost pressure is not within an acceptable operating range of a desired boost pressure.</p> |
