Technical Description of OBD-II Trouble Code
Malfunction in the Vent Control Circuit of the Evaporative Emission Control System
What does that signify?
This diagnostic trouble code (DTC) is a generic OBD-II powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may vary depending on the model.
The Evap vent valve serves the purpose of sealing the vent so that the EVAP system can pressurize and ensure there are no leaks. The Evap vent valve is typically supplied with 12V battery voltage when the key is turned on.
The ECM’s driver controls the ground and, when grounded, activates the valve (closing it). If the ECM detects a short to ground, an open, or a short to battery voltage on the control circuit, P0446 will be set. The code may also indicate that the ECM has detected that the EVAP system is unable to achieve or maintain vacuum during testing.
Symptoms
There will be no obvious symptoms for the driver, other than the illumination of the Malfunction Indicator Lamp (MIL).
Causes
A code P0446 could indicate one or more of the following:
Possible Solutions
If you have a P0446 OBD-II trouble code, here are some things you can try:
Other EVAP DTCs: P0440 – P0441 – P0442 – P0443 – P0444 – P0445 – P0447 – P0448 – P0449 – P0452 – P0453 – P0455 – P0456
