P0446: Evaporative Emission System Vent Control Circuit
What to do
Driveable with no symptom. Will fail an emissions test. Corrosion at the connector under the vehicle is a common cause and worth checking first.
What this code means
A fault in the circuit controlling the evaporative vent valve. The vent valve is what makes leak testing possible: it is open in normal running so the canister can breathe, and the module closes it to seal the system before a test.
Its position is the reason it fails. Mounted near the canister under the vehicle, it is exposed to road spray, salt and dirt, and both the valve and its connector corrode. On vehicles driven on salted roads this is among the more common evaporative faults, and the connector is worth inspecting before the valve is condemned.
Likely causes
Start here
- Faulty EVAP vent valve · moderate
- Corroded or loose connector · easy
- Open or shorted solenoid winding · moderate
- Road damage to underfloor wiring · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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