| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality diagnostic device for an evaporation purge system highly precisely diagnosing the abnormality in an early stage even in the case where pressure change phases are changed in an evaporator channel by various factors. SOLUTION: The channel inside of this evaporation purge system is decompressed and, when the pressure in the channel inside becomes a prescribed pressure or less, the channel inside is tightly closed. The pressure change amounts per a unit timeΔP(i),δP(i+1),... right after the tight closing are monitored under the prescribed pressure value P(i), P(i+1),.... When all of the pressure change amountsΔP(i),ΔP(i+1),... are a first judgment value (B) or more and all the change rates (ΔP(i)/ΔP(i+1)), (ΔP(i+1)/ΔP(i+2)),... of the pressure change amounts are second judgment values (C, D, E) or less, it is judged to be abnormal.
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