P0446: Evaporative Emission System Vent Control Circuit
Low SeveritySafe to drive (short-term)EVAP System
P0446 means the ECU has detected a problem with the EVAP vent control circuit. The vent valve controls airflow through the charcoal canister that captures fuel vapours. When the valve or its circuit fails, the EVAP system cannot properly purge or seal, triggering this code.
What does P0446 mean?
P0446 means the ECU has detected a problem with the EVAP vent control circuit. The vent valve controls airflow through the charcoal canister that captures fuel vapours. When the valve or its circuit fails, the EVAP system cannot properly purge or seal, triggering this code.
P0446 is a evap system-related diagnostic trouble code classified as low severity. When your vehicle's ECU detects this condition, it stores P0446 and illuminates the check engine light.
What are the symptoms of P0446?
If your vehicle has triggered P0446, you may notice one or more of these symptoms:
Check engine light illuminated
No noticeable driveability symptoms
May fail emissions test
Possible faint fuel smell near the rear of the vehicle
Fuel tank may not pressurize correctly during EVAP self-test
What causes P0446?
Here are the most common causes of P0446, ranked by how likely they are to be the culprit:
highFailed EVAP vent valve (solenoid stuck open or closed)
mediumWiring or connector issue at vent valve
mediumBlocked or kinked vent hose between canister and vent valve
lowCharcoal canister saturated or damaged
lowFaulty gas cap not sealing properly
lowSpider webs or debris blocking the vent filter
Is it safe to drive with P0446?
Generally yes, for short-term driving. Completely safe to drive. The EVAP system controls fuel vapour emissions and has no effect on engine performance or safety. The only consequence is a lit check engine light and emissions test failure.
How do you diagnose P0446?
Follow these steps to pinpoint the root cause of P0446:
Check gas cap for proper seal. Tighten and clear the code. If it returns, the cap is not the issue
Locate the EVAP vent valve (usually near the charcoal canister, rear of vehicle or near fuel tank)
Test vent valve with a scan tool: command it closed and listen for a click. No click means the solenoid has failed or has no power
Check wiring and connector at the vent valve for corrosion, damage, or rodent chew marks
Inspect the vent hose from canister to vent valve for kinks, cracks, or blockage
Check the vent filter (if accessible) for debris or spider web blockage
How much does P0446 cost to fix?
Repair costs for P0446 vary depending on the root cause and your vehicle. Here are typical estimates:
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace gas cap
€10–€30
€0–€0
€10–€30
Easy
Replace EVAP vent valve/solenoid
€30–€120
€40–€150
€70–€270
Moderate
Repair wiring or connector at vent valve
€5–€20
€40–€120
€45–€140
Moderate
Replace charcoal canister
€80–€250
€60–€200
€140–€450
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0446 on specific vehicles
P0446 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
P0446 on Toyota Camry
Toyota Camry • 2007-2024
Toyota Camry EVAP vent valves are located near the charcoal canister at the rear of the vehicle. The valve is a simple two-wire solenoid. Toyota's EVAP self-test runs during specific drive conditions, so the code may take several drive cycles to appear or clear. Common on high-mileage Camrys in humid climates where corrosion affects the valve connector.
What causes P0446 on a Toyota Camry?
Toyota CamryVent valve connector corrosion in humid climates
Toyota CamryStandard solenoid wear at 120,000+ km
P0446 on Honda Civic
Honda Civic • 2006-2024
Honda Civics have the EVAP vent valve integrated near the fuel tank. Access may require partial removal of rear interior trim or underbody panels. The 2016+ 1.5T models have a revised EVAP system. Honda's EVAP testing is sensitive, so even minor connector issues can trigger P0446.
Honda CivicSensitive EVAP testing on 1.5T triggers code from minor connector issues
P0446 repair cost for Honda Civic
Estimated costs for Honda Civic ownersadjusted lower than average due to Honda-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace gas cap
€9–€27
€0–€0
€9–€27
Easy
Replace EVAP vent valve/solenoid
€27–€108
€36–€135
€63–€243
Moderate
Repair wiring or connector at vent valve
€5–€18
€36–€108
€41–€126
Moderate
Replace charcoal canister
€72–€225
€54–€180
€126–€405
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0446 on Volkswagen Golf
Volkswagen Golf • 2005-2024
VW EVAP systems use an N80 purge valve and a separate vent valve. P0446 on the Golf typically points to the vent valve near the charcoal canister. On some model years, the canister is mounted inside the rear bumper area, making access tight. The N80 purge valve is a separate component and triggers different codes (P0441, P0443).
What causes P0446 on a Volkswagen Golf?
Volkswagen GolfVent valve failure near charcoal canister (rear bumper area)
Volkswagen GolfTight canister mounting location increases labour time on some model years
P0446 repair cost for Volkswagen Golf
Estimated costs for Volkswagen Golf ownersadjusted higher than average due to Volkswagen-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace gas cap
€12–€35
€0–€0
€12–€35
Easy
Replace EVAP vent valve/solenoid
€35–€138
€46–€173
€81–€311
Moderate
Repair wiring or connector at vent valve
€6–€23
€46–€138
€52–€161
Moderate
Replace charcoal canister
€92–€288
€69–€230
€161–€518
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0446 on BMW 3 Series
BMW 3 Series • 2006-2024
BMW EVAP systems are more complex than most, with multiple valves and a fuel tank leak detection pump. P0446 on a BMW may also involve the leak detection pump or its associated wiring. The charcoal canister and vent valve are typically accessible from under the rear of the car. BMW-specific scan tools provide more detailed EVAP test results than generic OBD2 scanners.
What causes P0446 on a BMW 3 Series?
BMW 3 SeriesLeak detection pump involvement in EVAP circuit on BMW
BMW 3 SeriesComplex multi-valve EVAP system requires BMW-specific diagnostics
P0446 repair cost for BMW 3 Series
Estimated costs for BMW 3 Series ownersadjusted higher than average due to BMW-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Replace gas cap
€14–€42
€0–€0
€14–€42
Easy
Replace EVAP vent valve/solenoid
€42–€168
€56–€210
€98–€378
Moderate
Repair wiring or connector at vent valve
€7–€28
€56–€168
€63–€196
Moderate
Replace charcoal canister
€112–€350
€84–€280
€196–€630
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related diagnostic codes
These codes are often seen alongside P0446 or indicate related issues:
P0440P0441P0442P0443P0455
Common questions about P0446
Can I drive with P0446?
Yes, completely safe. The EVAP system only controls fuel vapour emissions. No effect on engine performance or safety. You'll fail emissions testing though.
What is the EVAP vent valve?
A solenoid-controlled valve that allows fresh air into the charcoal canister during purge cycles. When the ECU tests the EVAP system for leaks, it closes the vent valve to seal the system. If it can't close or the circuit fails, P0446 is set.
Can a bad gas cap cause P0446?
Rarely. A bad gas cap more commonly triggers P0440 or P0455 (large leak). P0446 specifically points to the vent control circuit, not a general leak. But checking the cap first is free and takes 10 seconds.
How much does it cost to fix P0446?
The vent valve itself costs 30-120 euros. Labour is 40-150 euros since the valve is usually accessible near the rear of the vehicle. Total: 70-270 euros for most vehicles.
