P0446: Evaporative Emission Control System Vent Control Circuit Malfunction
Is your scanner showing P0446?
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P0446: Evaporative Emission Control System Vent Control Circuit Malfunction
OVERVIEWWhat Does The P0446 Code Mean?
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.
Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied 12V battery voltage with key on.
The ECM’s driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open, or a short to battery voltage on the control circuit, P0446 will set. Code also may refer to ECM detecting that EVAP system is unable to achieve or maintain vacuum during test.
P0446 wiring diagram
What Are The Symptoms Of The P0446 Code?
There will be no obvious symptoms to driver, other than Malfunction Indicator Lamp (MIL) illumination.
What Are The Potential Causes Of The P0446 Code?
A code P0446 could mean one or more of the following has happened:
- Faulty vent valve
- Open, short or excessive resistance on Vent valve control circuit
- Blockage of vent valve
- Bad PCM
How Can You Fix The P0446 Code?
With a P0446 OBD-II trouble code, here are some things to try:
- Replace Vent valve
- Repair open, short, or resistance problem in control circuit
- Repair open, or short, or resistance problem in power circuit
- Replace PCM
Other EVAP DTCs: P0440– P0441– P0442–P0443– P0444– P0445– P0447– P0448– P0449– P0452– P0453– P0455– P0456
Recommended Parts
Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:
>>> Evap Canister Vent Valve
>>> Twippo 372Pcs Waterproof Wire Connectors Kit
>>> ECU
>>> Autel Scanner MaxiCOM MK808S
Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!
Check This Video For Reference
P0446 Infographic - 1 Minute Summary
Reference Sources
Diagnostic Trouble Code (DTC) Charts and Descriptions for P0446 – Page 71.
