OBD-II diagnostic trouble code
P0446Safe to drive
Evaporative Emission System Vent Control Circuit Malfunction
The valve that vents the EVAP system to atmosphere isn't responding correctly, which can prevent the system's self-test from completing properly.
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Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
Frequently asked questions
Can I drive with P0446?
In most cases, yes — P0446 is generally not an urgent safety issue and the car is usually safe to drive for a while. Still, get it checked soon, since the underlying cause can affect fuel economy or emissions the longer it's left.
How much does it cost to fix P0446?
The cost varies too much by cause and vehicle to give a single figure here — a diagnosis will narrow it down.
What causes P0446?
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief