Faulty vent valve (solenoid). Blocked vent filter or hose. Wiring fault to vent valve. Spider webs or debris blocking vent. Faulty ECM driver (rare).

Which cars are affected by P0446?

P0446 is most commonly reported on Toyota, Nissan, Honda, Chevrolet, Ford vehicles, but can appear on any make.

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P0446

Low severity

EVAP Vent Control Circuit Malfunction

The EVAP system vent valve or its control circuit has a fault. The vent valve allows fresh air into the charcoal canister during purge cycles and seals the system during leak testing.

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Common causes of P0446

1Faulty vent valve (solenoid)

2Blocked vent filter or hose

3Wiring fault to vent valve

+2 more causes

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Commonly affected vehicles

ToyotaNissanHondaChevroletFord

P0446 can appear on any vehicle — these are the makes where it is most frequently reported.

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Related fault codes

P0171Medium

System Too Lean (Bank 1)

P0300High

Random/Multiple Cylinder Misfire Detected

P0420Medium

Catalyst System Efficiency Below Threshold (Bank 1)

P0172Medium

System Too Rich (Bank 1)