| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that failure of a variable valve timing mechanism may not be detected since operation change quantity of a variable valve timing mechanism during EGR control is a minute demand value in a light load zone in an engine including an EGR device and the variable valve timing mechanism. SOLUTION: In an internal combustion engine including an exhaust gas recirculation device re-circulating part of exhaust gas and mixing the same with suction air, and the variable valve timing mechanism varying valve open timing of at least an exhaust valve and an intake valve, target valve opening of the variable valve timing mechanism is advanced to first prescribed value at a timing advance side during control of the exhaust emission recirculation device, the target valve opening is advanced to a second prescribed value which is at a more timing advance side than the first prescribed value when difference between the first prescribed value and actual timing advance value exceeds a first determination range, and abnormality due to fixation of the variable valve timing mechanism is detected when difference between the second prescribed value and actual timing advance value exceeds a second determination range. COPYRIGHT: (C)2011,JPO&INPIT
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