P1446

Code

NISSAN P — Powertrain

EVAP Canister Vent Control Valve Closed

Brand: NISSAN

Type: P — Powertrain

Views: UK: 26 EN: 30 RU: 40

AI status

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Page language: EN

Causes

Stuck or mechanically seized canister vent control valve (vent solenoid)
Open or shorted wiring to the vent valve (connector corrosion, broken wire)
Faulty vent valve ground or power circuit (blown fuse, poor PCM ground)
Faulty PCM or EVAP control circuit
Debris or contamination blocking the vent path or valve
Incorrect installation or damaged vacuum/vent hoses

Symptoms

Malfunction Indicator Lamp (MIL) or Check Engine Light illuminated
Possible failed emissions test
Fuel odor near vehicle or around the charcoal canister
Difficulty refueling (fuel nozzle clicks off frequently) or EVAP pressure anomalies
Generally no drivability issues (engine runs normally) in many cases

What to check

Read freeze frame and readiness status with a scan tool; confirm P1446 is current
Visual inspection of vent valve, connector, wiring harness and nearby components for damage or corrosion
Check EVAP fuse(s) and PCM power/ground circuits
Backprobe vent valve connector and verify control voltage/ground while commanding the valve with a scan tool
Measure coil resistance of the vent valve with an ohmmeter
Smoke test EVAP system to find restrictions, blockages or leaks around the vent path

Signal parameters

Supply voltage to vent control valve: ~12 V (battery) when commanded (varies by vehicle); should be near battery voltage when energized
Control signal: PCM switches ground or +12V depending on design; check with backprobe while commanding
Typical vent solenoid coil resistance: commonly ~20–40 ohms (manufacturer specific; measure at ambient temperature)
Expected behavior: valve should change state (open/close) when commanded by scan tool; continuity present across coil when intact
No voltage or constant closed signal when PCM commands open indicates wiring/valve fault

Diagnostic algorithm

Verify the code: Use a scan tool to confirm P1446 is stored and note freeze frame data and related EVAP codes.
Visual inspection: Check vent valve, vacuum/vent hoses, charcoal canister area and wiring for damage or contamination.
Check fuses/grounds: Inspect EVAP-related fuses and PCM grounds; repair any corrosion or open circuits.
Resistance test: Unplug vent valve and measure coil resistance. Compare to expected range in service manual.
Command test: Backprobe valve connector and command vent valve with a scan tool. Observe control voltage and whether valve changes state.
Apply bench power: If safe, remove valve and apply appropriate battery voltage to verify mechanical operation (observe movement/sound).
Wiring check: If valve is mechanically good but not responding, perform continuity and short-to-ground/short-to-voltage checks on the harness between the valve and PCM.
Smoke test: Introduce smoke into EVAP system to locate blockages or misroutes preventing valve from venting or opening.
PCM check: If wiring and valve are OK but signal is absent/erratic, consider PCM circuit diagnostics per service manual before replacement.
Repair and retest: Replace faulty valve or repair wiring as needed, clear codes, run readiness/EVAP tests and confirm code does not return.

Likely causes

Failed/stuck vent control solenoid (most common)
Corroded/loose electrical connector at vent valve
Damaged wiring harness from heat/chafing near fuel tank
Blown EVAP-related fuse or damaged relay
Obstructed vent line or charcoal canister contamination

Fault status

⚠️ Status

The PCM detected the EVAP canister vent control valve is closed (or reports a closed state) when a different state was expected during system testing. This indicates a possible stuck valve, wiring fault, or control circuit failure affecting the EVAP venting function.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

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P1446 — EVAP Canister Vent Control Valve Closed