Possible causes

– EVAP control system pressure sensor
– EVAP canister purge volume control solenoid valve (The valve is stuck open.)
– EVAP canister vent control valve
– EVAP canister
– Hoses (Hoses are connected incorrectly or clogged.)

Tech notes

There is a factory service bulletin for the following Nissan models:

2002 Nissan Altima
2003 Nissan Altima
2004 Nissan Altima
2005 Nissan Altima
2002-2005 Nissan Altima Service Bulletin OBDII Code P1444

When is the code detected?

The canister purge flow is detected during the specified driving conditions, even when EVAP canister purge volume control solenoid valve is completely closed.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1444 NISSAN 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 Engine Control Module (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.

NISSAN Technical Service Bulletins for P1444 code