P0446: Evaporative Emission Control System Vent Control Circuit Malfunction
Can you still drive? Yes, this does not affect driveability. It is an emissions system issue only.
What Does P0446 Mean?
Code P0446 indicates a problem with the EVAP system vent control circuit. The vent valve allows fresh air into the charcoal canister during purge cycles and seals the system during leak tests. When the ECM detects an electrical or mechanical fault in the vent valve circuit, P0446 is set.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Faulty EVAP vent valve or solenoid
- Corroded or damaged wiring to vent valve
- Blocked vent valve filter
- Poor electrical connection at vent valve
- Faulty ECM in rare cases
Symptoms
- Check engine light on
- Possible fuel odor near the rear of vehicle
- Difficulty filling gas tank
- Failed emissions test
Diagnostic Steps
- 1Check EVAP vent valve connector for corrosion or damage
- 2Test vent valve solenoid operation with scan tool
- 3Measure resistance of vent valve solenoid
- 4Inspect wiring harness between ECM and vent valve
- 5Check vent valve filter for blockage
- 6Test vent valve with 12V power supply
Recommended Parts & Tools
EVAP canister vent valve
electrical connector cleaner
wiring repair kit
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $75 - $500 |
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Chat with AI About P0446Commonly Affected Vehicles
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Frequently Asked Questions
Where is the EVAP vent valve located?
The EVAP vent valve is usually located near the charcoal canister, which is typically under the vehicle near the fuel tank or in the engine compartment.
Can P0446 cause hard starting?
In rare cases, a stuck-closed vent valve can cause pressure buildup in the fuel tank, making it harder to start the engine.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
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