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General Information





General Description

The purpose of the Evaporative Emission Control System is to capture the fuel vapors (HC) that would escape from the fuel system. Gasoline vapors from the fuel tank and throttle body are collected in a charcoal canister. When the engine is running, the ECM can command the purge valve open which allows the fuel vapors to be pulled into the intake manifold from the canister. To test the system, the ECM will close off the Canister Close Valve and then open the Purge valve. The Purge valve is then closed, trapping a vacuum in the Evaporative Emission Control. If this vacuum decays too quickly it indicates a leak in the system and the ECM will set a code. The FTPS is used for monitoring pressure and vacuum levels in the fuel tank during the purge cycle and leak checking.

DTC Description

Checking output signals from fuel tank pressure sensor under Evap.system test, if fuel tank's vacuum decay slope is higher than prescribed threshold, ECM sets P0456.

DTC Detecting Condition