LEAK DIAGNOSIS SYSTEM USING ACTIVE PURGE PUMP AND LEAK DIAGNOSIS METHOD USING ACTIVE PURGE PUMP

An evaporated gas leak diagnosis method using an active purge pump is provided to detect a leak of the evaporated gas from a canister in a fuel system. The method includes diagnosing a failure of an active purge pump based on a signal generated by a pressure sensor installed on a vent line that extends from the canister to the atmosphere. The active purge pump is mounted on a purge line for connecting the canister with an intake pipe.