P0446
EVAP System Vent Control Circuit
EVAP / emissions
Generic OBD-II
Low
What it means
P0446 means the ECM has found a fault in the electrical circuit or operation of the EVAP vent control valve — the solenoid that lets the charcoal canister breathe and seals it for leak tests. It won't change how the car drives; it's an evaporative-emissions fault that keeps the check-engine light on and will fail a smog check until repaired.
Low
Can I keep driving? Safe to drive — this is an emissions fault that won't affect how the car runs, but it keeps the check-engine light on and will fail a smog check.
Common symptoms
What you'll notice
- Check-engine light on
- Fails an emissions / smog test
- Occasional fuel vapor odor near the vehicle
Common causes
Most likely first
- Faulty EVAP vent control valve (solenoid)Likely
- Blocked, dirty, or disconnected vent hose or canister filterCommon
- Damaged or corroded wiring/connector at the vent valveCommon
- Rarely, a failing ECMLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to confirm the code and conditions.
- Inspect the vent valve connector and wiring for damage or corrosion.
- Test the vent solenoid's resistance and that it clicks/actuates when commanded.
- Check the vent hose and canister filter for blockage or dirt.
- Replace the vent control valve if it fails testing, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0446?+
Yes — it's an emissions circuit fault and won't affect driveability. It will keep the light on and fail an emissions test, so fix it when convenient.
Can I just clear P0446?+
You can, but it will return once the ECM re-runs its EVAP self-test unless the vent valve or its wiring is actually repaired.
Related codes
Often seen with P0446
Read & clear P0446 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX