What is code P0446, how to fix it, and what vehicles are affected?

What is code P0446, how to fix it, and what vehicles are affected?
September 7, 2023
What is code P0446, how to fix it, and what vehicles are affected?

What does code P0440 mean?

Code P0440 is a diagnostic trouble code (DTC) that indicates a problem with the evaporative emission control (EVAP) system purge control circuit. The EVAP system is designed to prevent fuel vapors from escaping into the atmosphere. The purge control valve is responsible for regulating the flow of air from the charcoal canister into the engine, where the fuel vapors are burned.

Code P0440 and code P0446 are often related, as they both affect the EVAP system. However, there are some key differences between the two codes. Code P0446 is specific to the vent control valve, while code P0440 is specific to the purge control valve.

What causes code P0446?

There are a number of possible causes for code P0446, including:

What are the symptoms of code P0446?

In some cases, there may be no noticeable symptoms associated with code P0446. However, in other cases, the vehicle may experience:

  • A check engine light illuminated
  • Difficulty starting the vehicle
  • Poor fuel economy
  • Rough idle
  • Increased emissions

What vehicles are affected by code P0446?

Code P0446 can affect a wide variety of vehicles, including:

How to fix code P0446

The first step in fixing code P0446 is to diagnose the cause of the problem. This can be done by connecting a scan tool to the vehicle's OBD-II port. The scan tool will display the code and any other relevant information.

Once the cause of the problem has been diagnosed, the appropriate repairs can be made. If the vent control valve is faulty, it will need to be replaced. If there is a vacuum leak in the EVAP system, it will need to be repaired. If the charcoal canister or EVAP system pressure sensor is faulty, it will need to be replaced.

P0446 (Chevy, Ford, GMC Sierra)

For Chevrolet Silverado, GMC Sierra, and Ford F-150 vehicles, code P0446 is often caused by a faulty vent control valve. The vent control valve is located on the charcoal canister, which is typically located under the vehicle in the rear passenger side area.

To access the vent control valve, you will need to raise the vehicle on jack stands and remove the rear wheel. Once the wheel has been removed, you should be able to see the charcoal canister. The vent control valve is located on the top of the canister.

To replace the vent control valve, simply disconnect the electrical connector and unscrew the valve from the canister. Be careful not to spill any fuel vapor when removing the valve. Once the old valve has been removed, install the new valve in reverse order.


Ready to upgrade your vehicle or make essential repairs? Head over to Partshawk now and explore our wide range of high-quality automotive parts. Don't wait – give your vehicle the care it deserves! Click here to shop now.

Related posts
Powered by Amasty Magento 2 Blog Extension

Subscribe to newsletter

Copyright © 2013-present PartsHawk, LLC. All rights reserved.