P0446 on Ford
Evaporative Emission Control System Vent Control Circuit
P0446 on Ford vehicles indicates evaporative emission control system vent control circuit. Au7o has documented this code across 1 Ford model — most commonly on F-150. This emissions code points to a problem in the evaporative emission (EVAP) system's vent control circuit, which manages the vent valve that lets the charcoal canister breathe and seals it during leak tests. The EVAP system captures fuel vapors from the tank to keep them out of the atmosphere, and the vent valve must open and close on command for the system to work and self-test. The code sets when the engine computer detects an electrical or performance fault with this vent valve or its circuit. It usually causes only a check engine light with no driveability change, but it does prevent proper EVAP leak monitoring. Typical repair costs on Ford range from $60 to $320, depending on the specific model and root cause.
Common Causes of P0446
- •Faulty EVAP vent control valve (solenoid)
- •Wiring or connector fault in the vent valve circuit
- •Vent valve clogged with dirt, debris, or spider webs
- •Damaged or corroded vent valve connector
- •Blocked or pinched vent hose or filter
- •Faulty charcoal canister assembly
- •Faulty engine control module driver circuit
P0446 on Ford by Model
Ford F-150(1 issue)
- EVAP Canister Purge Valve Stuck Open — Hard Start After Refueling, Rough Idle, P0455/P04962011-2020
The EVAP canister purge valve (purge solenoid) on F-150s commonly sticks in the open position, allowing raw fuel vapor from the charcoal canister to be pulled into the intake when it shouldn't be. This floods the cylinders with vapor — owners report a vehicle that cranks but won't start (or stumbles badly) immediately after filling the tank, then runs fine once it clears. A stuck-open or leaking purge valve, along with cracked/collapsed lines between the canister, valve, and intake manifold, is the most common trigger for P0496 (EVAP flow during a non-purge condition) and a frequent cause of P0455/P0442 large/small leak codes. Ford issued TSB 19-2132 covering loose EVAP hose connections on 2018-2019 trucks. The check-engine light is the usual first symptom; drivability impact ranges from none to hard-start/rough-idle. The real OEM purge valve part number is AU5Z-9C915-B (aftermarket cross-refs: Dorman 911-222, Standard CP1-prefix units).
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What does P0446 mean on Ford?▼
P0446 stands for "Evaporative Emission Control System Vent Control Circuit." This emissions code points to a problem in the evaporative emission (EVAP) system's vent control circuit, which manages the vent valve that lets the charcoal canister breathe and seals it during leak tests. The EVAP system captures fuel vapors from the tank to keep them out of the atmosphere, and the vent valve must open and close on command for the system to work and self-test. The code sets when the engine computer detects an electrical or performance fault with this vent valve or its circuit. It usually causes only a check engine light with no driveability change, but it does prevent proper EVAP leak monitoring. On Ford specifically, this code is documented across 1 model.
What causes P0446 on Ford vehicles?▼
Common causes on Ford: Faulty EVAP vent control valve (solenoid), Wiring or connector fault in the vent valve circuit, Vent valve clogged with dirt, debris, or spider webs, Damaged or corroded vent valve connector, Blocked or pinched vent hose or filter. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0446 on a Ford?▼
Repair costs on Ford range from $60 to $320, depending on the specific model and root cause.
Which Ford models have P0446 documented?▼
Au7o has documented P0446 on 1 Ford model: F-150.