Leakage detector for fuel vapor treatment device

A leakage detector for a fuel vapor treatment device, comprising:

• a canister including a purge port;
• a purge passage connecting the purge port of the canister and an intake passage;
• a shutoff valve disposed along the purge passage, wherein the shutoff valve has an opened position and a closed position;
• a purge control valve disposed along the purge passage between the intake passage and the shutoff valve, wherein the purge control valve has an opened position and a closed position;
• a purge passage pressure detector disposed along the purge passage between the shutoff valve and the purge control valve;
• and
• a control unit configured to determine a leakage in the purge passage, wherein:
• the control unit is configured to shift the purge control valve and the shutoff valve to a first state with the purge control valve in the opened position and the shutoff valve in the closed position;
• the control unit is configured to shift the purge control valve and the shutoff valve from the first state to a second state with the shutoff valve in the closed position and the purge control valve in the closed position;
• the control unit is configured to compare a first purge passage pressure acquired from the purge passage pressure detector after the purge control valve and the shutoff valve are shifted from the first state to the second state, with a second purge passage pressure acquired from the purge passage pressure detector after a predetermined time after the purge control valve and the shutoff valve are shifted to the second state;
• and
• the control unit is configured to determine the leakage in the purge passage when the second purge passage pressure is higher than the first purge passage pressure by a predetermined amount or more based on the comparison.