Canister Vent Valve: Description and Operation

NOTE: It both DTC P0440 and P0446 are displayed, perform TROUBLE DIAGNOSIS FOR P0446 first.







COMPONENT DESCRIPTION
The EVAP canister vent control valve is located on the EVAP canister and is used to seal the canister vent.
This solenoid (the EVAP canister vent control valve) responds to signals from the 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 evaporative loss system components.
This solenoid valve is used only for diagnosis and usually remains opened.
When the vent is closed, under normal purge conditions, the evaporative loss system is depressurized and allows "EVAP Control System (Small Leak)" diagnosis.