| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a failure diagnostic device capable of accurately diagnosing a failure of an exhaust gas recirculation (EGR) device. <P>SOLUTION: An engine ECU carries out a program including the steps of determining the establishment of the failure monitor conditions of the EGR device (Yes in S100), fixing to the maximum delay side in a VVT control system (S110), introducing the EGR device (S130), determining the lapse of a predetermined time after the introduction of the EGR device (Yes in S140), measuring an actual value PMON of pressure in an intake pipe (S150), cutting off the operation of the EGR device (S160), determining the lapse of a predetermined time from the operation cut-off of the EGR device (Yes in S170), measuring an actual value PMOFF of pressure in the intake pipe (S180), and determining the EGR device to be normal (S200) when a value obtained by subtracting the actual value PMOFF of pressure in the intake pipe in the nonoperating state of the EGR device from the actual value PMON of pressure in the intake pipe in the operating state of the EGR device is larger than a predetermined determination value. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
