| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deterioration of detection accuracy caused by intake air pressure fluctuation, in a system for detecting intake air leakage from an internal combustion engine. SOLUTION: This intake air leakage detection system for the internal combustion engine includes: a first throttle valve disposed in the intake passage of the internal combustion engine; a second throttle valve disposed in an intake passage downstream of the first throttle valve; an intake pressure sensor acquiring pressure downstream of the second throttle valve; and a detection means performing vacuum processing for controlling the first throttle valve to a fully closed state to set a portion downstream of the first throttle valve in a vacuum state, and also detecting the intake air leakage based on intake pressure detected by the intake pressure sensor during the vacuum processing. The detection means damps intake pulsation by controlling the opening of the second throttle valve to a predetermined opening smaller than the fully opened state and larger than the fully closed state when performing the vacuum processing. COPYRIGHT: (C)2011,JPO&INPIT
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