DTC P2421-00: EVAP System Vent Valve Stuck Open: General Description

The Canister Close Valve (CCV) is located on the Evaporative emission system (EVAP) canister and is used to seal the canister vent. The CCV responds to signals from the Engine Control Module (ECM). When the ECM sends an "ON" signal, the coil in the solenoid valve is energized. A plunger will then move to seal the canister vent. The ability to seal the vent is necessary for the on board diagnosis of other EVAP control system components. The CCV is used only for diagnosis, and usually remains opened. When the vent is closed, under normal purge conditions, the EVAP control system is depressurized and allows EVAP control system (small leak) diagnosis.