What P0446 means
Evaporative Emission Control System Vent Control Circuit Malfunction
Common causes (general)
Before spending money on parts, verify the code with a scan tool and read freeze frame data. Freeze frame captures every sensor value at the moment the code set — this is often enough to figure out the root cause without further testing.
Manufacturer-specific descriptions
Different manufacturers use this code for slightly different failure modes. Here's what your specific make means by P0446:
| BMW | Evaporative Emission System Vent Control Circuit |
| FORD | Evap Emission Control System Vent Malfunction |
| MITSUBISHI | Evaporative Emission Control System Vent Control Circuit Malfunction; EVAP.emission vent solenoid |
| NISSAN | Evaporative Emission Control System Vent Control Circuit Malfunction |
| VOLKSWAGEN | EVAP Vent Solenoid Valve Control System |
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