Possible causes
– Faulty canister vent control valve
– Purge Control Valve harness is open or shorted
– Purge Control Valve electrical circuit poor connection
– Purge Control Valve harness is open or shorted
– Purge Control Valve electrical circuit poor connection
Tech notes
Before replacing any parts, check for damage EVAP canister and for loose hoses from the vent control valve to the canister.
When is the code detected?
An improper voltage signal is sent to Engine Control Module (ECM) through Evaporative Emission System (EVAP) canister vent control valve.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0447 SUBARU Description
The Evaporative Emission System (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 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 evaporative emission control 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 emission control system is depressurized and allows EVAP Control System (Small Leak) diagnosis.
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 emission control 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 emission control system is depressurized and allows EVAP Control System (Small Leak) diagnosis.