Ford Check Engine Code
P0446 on Ford
Evaporative Emission Control System Vent Control Circuit Malfunction
Also covers: Lincoln, Mercury
P0446 on Ford: what makes it different
P0446 shows up often on Ford vehicles because the EVAP vent valve — which opens to atmosphere during non-purge conditions — is mounted low near the fuel tank on many Ford trucks and crossovers, exposing it to road debris, corrosion, and rodent damage that block or stick the valve.
Most-affected engines
- 2.5L/3.0L (Escape, Fusion)
- 5.4L/5.0L V8 (F-150)
- 2.0L EcoBoost (Escape, Edge, Focus)
Common model years: 2008–2018
Most likely cause on Ford
Stuck or clogged EVAP canister vent valve/solenoid preventing proper airflow during the vent phase of the EVAP monitor.
Known Ford engine-family issues
Ford's EVAP vent solenoids on trucks and SUVs are often mounted underbody where they're exposed to salt, mud, and moisture, making corrosion-related sticking a recurring issue in colder or coastal climates.
Ford-specific causes (most common first)
- Vent valve stuck closed or clogged with dirt/debris (very common on trucks and SUVs with valves near the frame rail)
- Rodent-damaged wiring or chewed vent hose (common in vehicles parked outdoors)
- Charcoal canister filter contamination from age
- Corroded electrical connector at the vent solenoid
- Loose or missing fuel cap (should be ruled out first, cheapest fix)
Ford-specific diagnostic tip
Use a smoke machine or scan tool EVAP test on Ford models to actuate the vent valve directly — if you hear it click but airflow doesn't change, the valve is likely mechanically stuck rather than electrically failed, which points you straight to a valve replacement instead of chasing wiring.
Symptoms drivers report
- Check engine light
- Possible slow refueling / fuel gushing back
Typical repair cost on Ford
Most Ford owners fix P0446 for between $100 and $350, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Stuck or clogged EVAP canister vent valve/solenoid preventing proper airflow during the vent phase of the EVAP monitor. — before throwing parts at it.
Ford P0446 FAQ
Will a loose gas cap cause P0446 on a Ford?
It can trigger EVAP codes, but P0446 specifically points to the vent path being blocked rather than a leak, so check the cap but expect the vent valve or canister to be the real cause.
How urgent is P0446 on a Ford truck?
It won't hurt drivability, but a stuck vent valve can eventually cause hard starts or fuel filling issues, and it will keep you from passing an emissions test until fixed.
Can rodents really cause this code on Ford vehicles?
Yes — Ford EVAP components and wiring near the fuel tank are a known target for rodents in vehicles that sit outside, especially trucks and SUVs with more open undercarriage space.
Related codes
Drive a different make? See the general P0446 guide for cross-vehicle causes and symptoms.
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Most common fix for P0446:
EVAP vent valveAs an Amazon Associate, AXLY earns from qualifying purchases. General P0446 guide →