EVAP System Vent Control Circuit
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.
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.
Real-world scan data
Appears alongside · share of P0446 scans
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
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.
P0446 by make
Based on commonly reported failure patterns across owner and repair communities, not on our scan data.
Chevrolet
On Chevrolet trucks and SUVs, the vent solenoid sits near the fuel tank and takes a lot of road dirt, so it is a common failure. Check the connector and wiring first.
Dodge
On Chrysler-built vehicles such as Dodge models, a failed vent solenoid or leak-detection part under the vehicle is a common cause. Look at the connector and wiring first.
Ford
On Ford trucks and SUVs, this points to the EVAP vent valve circuit, often the vent solenoid near the fuel tank or canister that can fail from corrosion and road grime. Check the connector and wiring first.
GMC
On GMC trucks and SUVs, the vent solenoid sits near the fuel tank and takes a lot of road dirt, so it is a common failure. Check the connector and wiring first.
Honda
On Hondas, the EVAP canister vent shut valve near the fuel tank is a common failure for this code. It can also be blocked by dirt or debris.
Jeep
On Jeeps, a failed vent solenoid or leak-detection part under the vehicle is a common cause, particularly where mud and salt collect. Look at the connector and wiring first.
Nissan
On Nissans, the EVAP canister vent control valve near the tank or canister is the usual suspect. Dirt and water in the valve are common causes of failure.
Toyota
On Toyotas, the canister vent valve or its wiring near the tank are the usual suspects. A fuel cap that does not seal can add related codes, so check it too.
FAQ
Quick answers
Is it safe to drive with P0446?+
Can I just clear P0446?+
Related codes
Read & clear P0446 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.