Ask Andy AIP0446 Evaporative Emission System Vent Control Circuit Malfunction
What it means, what causes it, and what it costs to fix.
What P0446 means
The vent valve, usually near the charcoal canister by the fuel tank, lets fresh air in and out of the EVAP system. The computer saw a problem with the valve or its circuit.
Can I drive with P0446?
Severity: Low. Not urgent. Fix it when convenient.
Safe to drive. You may have trouble filling the tank if the vent is stuck closed.
Get a diagnosis for your exact car
Tell Andy your year, make, model, and symptoms. You'll get best case, most likely, and worst case, with parts and labor costs. Free, in about 15 seconds.
Ask Andy about P0446Symptoms
- Check engine light
- Gas pump clicks off early when refueling
- Whoosh of air when removing the gas cap
Common causes
Most likely first.
- Failed vent valve or solenoid
- Vent valve clogged with dirt or spider webs
- Damaged wiring near the tank
- Clogged canister or vent filter
How to diagnose P0446
- Inspect the vent valve and its filter for dirt and debris. They sit under the car and get packed with road grime.
- Command the valve with a scan tool and listen for a click.
- Check the wiring and connector for corrosion.
Tip: most US auto parts stores will read your codes for free.
Repair costs
| Vent valve | $100–$300 installed |
| Vent filter or canister | $50–$700 |
Typical US prices. Your vehicle, region, and shop rates will change these.
P0446 FAQ
What does P0446 mean?
P0446 means "Evaporative Emission System Vent Control Circuit Malfunction." The vent valve, usually near the charcoal canister by the fuel tank, lets fresh air in and out of the EVAP system. The computer saw a problem with the valve or its circuit.
Can I drive with a P0446 code?
Safe to drive. You may have trouble filling the tank if the vent is stuck closed.
What is the most common cause of P0446?
The most common cause is: Failed vent valve or solenoid. Other causes include vent valve clogged with dirt or spider webs and damaged wiring near the tank.
How much does it cost to fix P0446?
Typical repairs run about $50 to $700 in the US, depending on the cause. Vent valve: $100–$300 installed.
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