Ford F150 P0446: EVAP Vent Control Circuit → Malfunction

This is one of the most commonly encountered trouble codes for the Ford F150 The Code P0446. This trouble code is a reference to a number given when you connect your F150 to an OBDII scan. It indicates that an error has occurred in the evaporative exhaust control system. This code is often found with P0440, P0441 or P0440.

P0446: Evaporative Emission Control System → Vent Control Circuit → Malfunction

The P0446 problem is not usually a serious threat to your car's driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. It's often associated with P0442. Another common code for trouble is P0420. It often comes with P0446.

Ford F150 P0446 OBDII Symptoms

The P0446 code is usually not accompanied with any obvious symptoms. Although the service engine light may come on soon, that's usually all. A slight drop in fuel economy is not uncommon. You may notice a gas-like odor when you use P0446. Because it is related to the fuel vapor system, P0446 may also cause a slight gas smell.

Ford F150 P0446 Meaning

The universal OBDII code P0446 can be used to diagnose trouble codes. It means that no matter what make or model vehicle you have, this code will be the same (F150). Technically, the code stands for:

Evaporative Emission Control System Vent Control Circuit Malfunction

The EVAP captures any fuel vapor in the fuel tank, and transmits them to engines intake for ignition. If the EVAP control circuit vent control circuit does not respond to the ECU it will throw the OBDII code P0446 and the service engine light soon will illuminate.

F150 P0446 Troublecode Causes

P0446 code can be triggered in Ford F150 by many factors. These are some of the more common issues that can trigger the P0446 trouble code in your Ford F150.

• Vapor Canister Purge Valve– One of the most common causes of the P0446 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips.
• EVAP System Hose– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This can lead to the code P0446. It should have a hole or tear.
• The Faulty Charcoal Caister– The charcoal canister is often the cause of P0446.
• Fuel Tank Sending Unit– It is possible for the fuel tank sending unit to go bad. It can cause a disruption in the line pressure, throwing off the code.
• Capacity for Fuel– A bad fuel cap can cause the code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. You may not get the message but a P0446. This will save you time and money.
• Fuel Filler Neck– There is often a gasket where the fuel filler neck connects with the gas tank. The gasket may dry out especially if the vehicle is in dry conditions. When it dries out, the fuel tank can’t hold pressure anymore.

Ford F150 Diagnosis - Page 0446

To diagnose the problem with your Ford F150's P0446, a mechanic can use a variety of tools. These are some of the common diagnostics that can be done for the code

• The mechanic will usually check for any additional trouble codes. A mechanic will usually check for additional trouble codes to help diagnose the problem. That’s because when they appear together in certain combinations, there will often only be only a few conditions that will throw any combination of codes at one time.
• Once the mechanic has determined the trouble codes associated with P0446, he or she will usually Check out the EVAP System. It includes the purge valve and line as well as the canister.
• To ensure that the cap can withstand pressure, the mechanic will check it. If you are getting a warning that your gas cap is off, even when it’s on, replacing it will more than likely clear this code.
• Monitor and check the pressure in your fuel tank.
• The mechanic will then perform the following tests after completing the above-mentioned checks:
• A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.

The Most Popular P0446 Fixes

These are some of the more common F150 P0446 fix:

• Replacement of gas cap
• Replacement for EVAP Line
• Replace charcoal canister
• Change the fuel tank

You should start with the gas caps and move on to the fuel tanks. This is because the gas caps are the easiest to replace and the least costly.

Here’s a great video on How to check your gas cap.

You will need to find the cause of your Ford F150 throwing the P0446 error code. This should help. Feel free to add anything below. You have a wonderful day.