P1446 Nissan EVAP canister vent control valve fault (valve closed)

EVAP canister vent control valve closed (Nissan)

Severity not verified — if the car runs badly, have it inspected

This is an EVAP emissions fault and owners report a check engine light and fuel blowing back at the pump, but no Nissan document read for this page rates how soon it needs attention.

Source: how we rate severity

P1446 in short

On Nissan vehicles, P1446 means the EVAP canister vent control valve is stuck or kept closed. Owners of Sentras and a Titan report fuel clicking off or blowing back while refuelling. A failed valve or a blocked canister is the usual cause. It is an emissions fault, but fix it before the pump trouble gets worse.

The Nissan EVAP system lets fresh air into the charcoal canister through a vent control valve. The computer closes the valve to seal the system for leak checks and opens it otherwise. P1446 is set when the valve does not behave as commanded and stays closed.

With the vent shut, air cannot leave the tank as fuel goes in, so the pump nozzle shuts off early or fuel comes back out of the filler. Several Nissan owners describe exactly this alongside the check engine light.

Replacing the valve alone did not hold in one Titan, where the code and blow-back returned within days. A Quest dealer found spider webs in the canister, so the canister and the vent path need checking as well.

Pick your make

P1446 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. EVAP canister vent control valve stuck closed

    Supported by vehicle data
    Why it ranks here
    The code names this valve and Nissan owners in several complaints had it diagnosed or replaced for P1446.
    What would change this
    Raises if the valve does not click when the scan tool commands it or the blow-back stops once the vent is opened; lowers if it works and the code returns.
    How to test the evap canister vent valve

  2. Blocked EVAP canister or vent path

    Supported by vehicle data
    Why it ranks here
    A Quest dealer found spider webs in the canister, and a Titan came back with the same code two days after a new vent valve.
    What would change this
    Raises if a new valve does not clear the symptom or the vent path restricts airflow; lowers if airflow through the canister and vent line is free.
    How to test the evap charcoal canister

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Note whether the fuel pump nozzle clicks off early or fuel blows back at the filler, and read the stored codes.

    Low riskTool: OBD-II scan tool

    • IfFuel clicks off or blows back and P1446 is stored

      It meansThe vent is probably closed, so test the valve and the vent path.

      Go to step 2

    • IfNo refuelling trouble and P1446 is stored

      It meansStill test the valve, as the fault may be intermittent.

      Go to step 2

  2. With a scan tool that can command the EVAP vent control valve, switch it on and off and listen for it to click; then check that air moves through the canister vent line.

    Best left to a shopTool: scan tool with active tests

    Warning:Fuel vapour is flammable: keep sparks and open flame away, and work with the vehicle on level ground. The canister and valve sit under the vehicle, so lifting it needs proper stands.

Symptoms

  • Check engine light
  • Fuel pump clicks off early or fuel blows back out of the filler when refuelling

Compare with: Check engine light came on after getting gas

How to fix

Parts and cost context

  • EVAP canister vent valve:Valve replacement alone did not hold in one Titan complaint, so ask the shop to check the canister and vent path too. Labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Nissan

  • 2004–2005 · Sentra

    Supported by vehicle data

    Three Sentra owners report P1446 as the EVAP canister vent control valve with fuel blowing back when refuelling (complaints 688389, 957880, 719248). No Nissan bulletin was found in the local cache.

  • 2004 · Titan

    Supported by vehicle data

    A 2004 Titan owner reports P1446 vent valve closed; a new vent valve solenoid cleared it for only two days (complaint 1431128).

  • 1999 · Quest

    Supported by vehicle data

    A 1999 Quest dealer diagnosed P1446 as a vent control valve and canister problem, with spider webs in the canister (complaint 374886).

No curated relationships for P1446 yet.

All EVAP (evaporative emissions) codes

P1446 questions

Why does fuel keep clicking off at the pump with P1446?

On Nissans the code means the vent valve is closed, so air cannot leave the tank as fuel goes in and the nozzle shuts off or fuel blows back.

Sources and review

  1. P1446 for Nissan — TroubleCodes.net
  2. NHTSA complaint ODI 688389: 2004 Nissan Sentra, fuel blows back at refuelling with P1446 — NHTSA (owner complaint)
  3. NHTSA complaint ODI 957880: 2005 Nissan Sentra, P1446 EVAP canister vent control valve — NHTSA (owner complaint)
  4. NHTSA complaint ODI 1431128: 2004 Nissan Titan, P1446 vent valve closed, repeat blow-back — NHTSA (owner complaint)
  5. NHTSA complaint ODI 374886: 1999 Nissan Quest, P1446 and spider webs in the canister — NHTSA (owner complaint)
  6. P1446 fault code information (Nissan) — TAT scan data codes
Last reviewed
Written by
Saurabh K.
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