Canister Purge Volume Control Valve: Description and Operation

P0443 EVAP Canister Purge Volume Control Solenoid




SYSTEM DESCRIPTION
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass passage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor from the EVAP canister is regulated as the air flow changes.




COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/OFF duty to control the flow rate of fuel vapor from the EVAP canister. The EVAP canister purge volume control solenoid valve is moved by ON/OFF pulses from the ECM. The longer the ON pulse, the greater the amount of fuel vapor that will flow through the valve.

P1447 Evaporative Emission (EVAP) Control System Purge Flow Monitoring




System Description
In this evaporative emission (EVAP) control system, purge flow occurs during non-closed throttle Conditions. Purge volume is related to air intake volume. Under normal purge Conditions (non-closed throttle), the EVAP canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP control system pressure sensor to intake manifold vacuum.