P0446 Canister Vent Solenoid Circuit

Code: P0446
Applies To: Most makes, generic code
Loose Cap Can Set It: Not named in our sources
Typical Fix: $182 at YourMechanic

A problem with the vent valve that lets fresh air in and out of the charcoal canister.
A shop confirms it with the carmaker's EVAP test and a smoke machine before replacing parts.
Usually yes for now, but get it fixed soon and check for open recalls.

What The Carmakers Call It

Canister Vent Solenoid Circuit, as printed by Ford Motor Company

Causes Named In Carmaker Bulletins

An open or shorted vent solenoid circuit (source)
Water, dirt or corrosion at the canister vent valve (2007 to 2010 GM full size SUVs and Avalanche) (source)

No source ranks these by how often they happen, so they are listed as the bulletins give them.

No source ties P0446 to the gas cap.

We did not find the generic J2012 wording for P0446 in a free primary source. Ford's name is shown.

What The Fix Costs

The usual part for this code is the vent valve. Published estimates put it at $182 at YourMechanic. The full table with every source and date is on the cost page. A diagnosis first keeps you from paying for a part you did not need, which is why we price what to do after a failed smog check before the fix.

Getting The Light To Go Off

After the repair the light goes off once the EVAP test runs and passes on three drive cycles in a row, and the code is erased after 40 warm up cycles, per CARB. The test only runs under set conditions such as a fuel level between about 15 and 85 percent, so it can take days.

P0447Evap Emission System Vent Control Circuit Open P0448Evap Emission System Vent Control Circuit Shorted P0449Evap Emission System Vent Valve/solenoid Circuit P2422Evap Canister Vent Shut Valve Stuck Closed Malfunction