P1446

Symptoms

• Check engine light
• reduced fuel efficiency
• possible fuel odor around the vehicle
• rough idle or stalling in some cases
• possible refueling difficulty because the tank cannot vent properly.

Probable causes

• 1) Vent control valve stuck closed (most cases per sources) - dust or debris jamming the mechanism
• or valve failure. 2) Faulty EVAP pressure sensor. 3) EVAP pressure sensor harness open or shorted
• or poor electrical connection in the circuit. 4) Blocked rubber tube to the vent control valve
• water separator problems
• or EVAP canister saturated with water. 5) Clogged vent filter/hose.

Diagnostic steps

1. Read codes and freeze frame with a scan tool; confirm P1446 is current.
2. Locate the vent control valve on the EVAP canister and inspect the rubber vent tube and filter for blockage, water or debris; check the water separator and whether the canister is saturated with water.
3. Test the vent control valve: command it with the scan tool (or apply battery power per service procedure) and verify it opens/closes freely; a valve that stays closed is faulty.
4. Inspect the valve connector and harness for opens, shorts and corrosion; check the EVAP pressure sensor circuit for poor connections.
5. Test/replace the EVAP pressure sensor if its readings are implausible.
6. Replace the vent control valve if stuck - sources report this is the repair in the large majority of Nissan/Infiniti cases.
7. Clear codes and confirm the EVAP monitor completes without resetting P1446.