| 摘要 |
PROBLEM TO BE SOLVED: To provide a failure detection system in an evaporable fuel treatment apparatus, the failure detection system being small in power necessary for leak determination.SOLUTION: A failure detection system in an evaporable fuel treatment apparatus comprises: the evaporable fuel treatment apparatus having a fuel tank 1 and a canister 3; a pressure sensor 11 which detects a pressure in a treatment system; a step-motor type CCV (Canister Closed Valve) 15 which maintains the inside of the treatment system in a sealed state; and an ECU 35 which controls these items. The failure detection system also performs leak determination of evaporable fuel on the basis of a pressure change amount when the inside of the treatment system is maintained in the sealed state. The CCV 15 is switched between opening/closing by energization, however, a valve-opened state and a valve-closed state are held in a non-energization state. The ECU 35 has a timer function, and performs the leak determination every prescribed time even during a stop state of a key-off vehicle. The ECU also performs pre-determination as indeterminant when a pressure change within a prescribed time is within a prescribed range prior to the execution of timer-type leak determination. |
