DTC P1444: EVAP Canister Purge Volume Control Solenoid Valve - Improper Flow Condition : Description

WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

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 (EVAP-CPVCSV) changes to control the flow rate. The EVAP-CPVCSV 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 airflow changes.

The EVAP-CPVCSV uses an ON/OFF duty to control the flow rate of fuel vapor from the EVAP canister. The EVAP-CPVCSV 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.