P0448 Toyota EVAP System Vent Control Circuit Shorted
– Purge Control Valve harness is open or shorted
– Purge Control Valve electrical circuit poor connection
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 componentsThis 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.