MALFUNCTION DIAGNOSIS EQUIPMENT FOR VAPORIZED FUEL TREATMENT DEVICE

摘要

PURPOSE: To provide a malfunction diagnosis equipment for a vaporized fuel device, capable of diagnosing a malfunction exactly without decreasing a diagnosis chance blindly even when the pressure in a tank increases suddenly owing to a slosh. CONSTITUTION: After the pressure in a fuel tank 1 is decreased to the predermined negative pressure P1, a malfunction diagnosis is made by observing the pressure increasing degree ΔP in the closed state isolated from the atmosphere. When diagnosing, comparing a pressure detecting value Pn in the fuel tank 1 with a reference value M increasing at the predetermined increasing rate, the renewal of the pressure detecting value Pn is interrupted while the pressure detecting value Pn exceeds the reference M, and the renewal of the pressure detecting value Pn restarts when the pressure detecting value becomes not greater than the reference value.