P0446: Evaporative Emission System Vent Control Circuit

What does P0446 mean?

The engine computer has found a problem with the EVAP vent valve or its control circuit. On many vehicles this is an electrical fault in the vent solenoid circuit; on others (notably older GM and Ford models) it can also be set when the system won't vent properly, such as a vent valve stuck closed or a blocked vent line.

Generic OBD-II definition: Evaporative Emission System Vent Control Circuit. Confirm applicability in your vehicle service information.

Common causes

• Faulty vent valve/solenoid
• Vent line or filter blocked by dirt, debris, or insect nests
• Wiring or connector issue in the vent valve circuit

Symptoms

• Usually no drivability symptoms
• Possible faint fuel smell
• Will likely fail an emissions inspection
• Possible trouble filling the tank

Can I keep driving with P0446?

Severity: Low Usually safe to keep driving, but get it checked.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Inspect vent valve and filter
• Check wiring