P0351 Ford F150 | Meaning, Causes, Symptoms & Solutions

Diagnostic Trouble Code (DTC) P0446 might appear on your Ford F150’s display when the vehicle is facing trouble with its evaporation system. Usually, Fords with 3.5L or 5.4L engine face this issue often.

The p012d code ford f150 means an error with the Evap System. Its technical form is Evaporative Emission Control System Vent Control Circuit Malfunction. The Evap system has only one job, to get fuel vapor and transfer it to the engine, which helps the engine to ignite the combustion process.

Solutions to this problem are pretty tricky for some people who do not know their Ford F150. But if you have enough confidence, you can fix it by yourself by following our steps below. Read the following article to learn more about code P0446.

What Does Code P0446 Mean on Ford F150?

DTC P0446 is one the most common universal trouble codes for any vehicle and Ford F150. When the Evap system fails to operate its work to ignite the engine in the normal combustion process, the code P0446 appears, and service engine soon light turns on.

Evap control system vent circuit sometimes goes faulty. In most cases, it doesn’t respond anymore or is short. As a result, ignition faces problems.

Here is the breakdown of Ford F150’s DTC P0446:

  • P = Powertrain related problem. Mainly problems refer to engine and transmission systems.
  • 0 = Intake Valve Control Solenoid Circuit Low
  • 4 = Oxygen (O2) Sensor Heater Circuit Malfunction
  • 4 = Injection Pump Fuel Metering Control on Bank “2” High. That can occur (Cam/Rotor/Injector)
  • 6 = Ignition Coil A Primary/ Secondary Circuit Malfunction 

Common Symptoms Of A P0446 Ford F150 Issue

When it comes to Ford F150, there are not many symptoms visible to error code P0446. There is only one visual symptom: Malfunction Indicator Lamp (MIL).

But, some noticeable things will alert you beforehand. You have to use your senses for things like smell and quantify fuel usage. We are going to discuss some symptoms below:

Service Engine Soon Light comes on (MIL)

Behind the steering wheel, on display where every piece of information pops up, there is a light that indicates malfunctions. When your Ford F150 is having trouble with the Evap system, the light turns on as an alert.

Light only appears when any DTC error happens. So, P0446 issues will turn on the service soon, and you will notice it immediately.

Fuel Economy Reduced Slightly 

Ford F150 has a mileage of 18 MPH on city roads and 24 MPH on highways. Average is at least 20 MPH. It is not the best, but suitable for a heavy truck.

When the Evap control system is not operating correctly, the mileage drops slightly. You might not notice at first because MIL doesn’t come on instantly, but it will show up after a while. Or if you are an efficient person, you will see it soon.

Fuel Odor around Ford F150 

Usually, Ford F150 doesn’t leak any fuel, or the smell of fuel around it is not ideal. Because fuel is stored in a sealed tank and odor coming out of it without leaking is impossible.

You may not notice it soon, but Ford F150 leaks fuel to some extent, even before the P0446 code appears. Unnoticed fuel creates an odor that becomes noticeable after a while.

Engine makes a hissing noise when Vapor Leaks Fuel

Ford F150’s DTC P0446 issues make the engine make some hissing sound. This noise is familiar to similar DTC codes, but if code P0446, you will understand that it is happening because of a fuel leak from the vapor chamber.

Engine intake or exhaust air and sometimes fuel gets mixed with air, and a leak causes fuel to come out and, while doing so, creates noise on the vapor vent.

Engine Misfires

DTC P0446 restricts some things on your Ford F150’s engine performance. When fuel leaks, the electronic control module seals the Evap system. ECM also detects short circuit and turn on the air vent control valve.

This causes the engine to misfire when it is about to start or even while running on roads.

What Are Some Potential Causes Of A P0446 Ford F150 Code

DTC P0446 issue happens to your Ford F150 for specific reasons. Most of the symptoms of this problem are invisible because it’s mostly internal. So, behind this internal issue, there are some potential causes.

Here are some of them: 

  • Faulty EVAP Canister Vent Control Valve
  • Vent valve control circuit open, short, or excessive resistance 
  • Blocked or clogged vent valve
  • Power Control Module (PCM) damage
  • Damaged Fuel tank sending unit
  • Fuel cap damaged/ missing
  • Fuel filler neck cracked

How To Diagnose And Fix P0446 Ford F150 Code

Diagnosing trouble codes is very straightforward, but fixing them can sometimes be difficult. You can get an OBD scanner to run a diagnosis on your Ford F150 and find the origin of the problem of DTC P0446. It is necessary to repair issues, or your gas will finish soon, gradually increasing your gas expenses.

There are several solutions to this problem, and we will try our best to help you as simply as possible. P0446 on Ford F150 indicates mainly fuel leak-related problems. So, if you can fix those problems by following our methods below, you can save a lot of cash by not going to a mechanic or dealership.

We are going to provide some common solutions for multiple problems.

Check out the solutions below: 

Repair EVAP System

The Evap system transfers fuel vapor from tank to engine to ignite combustion. So, if  EVAP is faulty or there’s any leak in the system, then there are high chances of the engine not operating correctly. You must diagnose DTC P0446 to repair it properly.

Check EVAP vent system by opening the hood and locating EVAP vent using a manual or service guide. If the EVAP system is not working, you can replace it (only if you are an expert). It is best to take it to a mechanic in that case.

Depending on issues, a mechanic will charge you From $125 to $400.

Repair Vent Valve Control Circuits

Use an OBD II scanner to find the exact cause of P0446 on your Ford F150. It is possible that the origin of the error code is Vent Valve Control Circuit. The circuit can be open or short, which caused this issue. As a result, the Vent valve control won’t work.

Open the front hood of your Ford F150 and again find the vent valve control circuit using a service manual which can be bought for only $15. Once you find it, if it is open, then reconnect the circuit. Test run to check if it’s working. If not, then you need to replace the circuit. Buy a new one and replace it.

New Vent Valve Control Circuit maybe cost around $18. You can find it at local repair shops too.

Replace or Clean Blocked Vent Valve

Replacing Blocked Vent Valve should be a second option as it costs a lot for the part only. Vent Valve assists in separating components of intake air from toxic materials. So after a while, it conceived dirt and other substances while restricting airflow and causing problems. This is when DTC P0446 appears on your Ford F150.

Using the service manual, locate the Vent Valve. It is underneath the Ford, and it has charcoal in it, which consumes the dirty material. Unplug it and clean it with a cleaner spray. Put it back and run the truck. Even after that, if the error doesn’t go away, you need to replace it. An expert is necessary as it is a sensitive part.

Vent Valve for Ford F150 costs $180. Cleaning spray is about $20.

Repair or Replace PCM

The Power Control Module can send a faulty signal even if there is no issue with your Ford F150. A diagnostic scanner can determine the main problem here. 

If you see a faulty signal, erase the PCM database by resetting it. But if resetting isn’t working, you need to replace it with a pre-programmed Power Control Module. Unplug the old one and install a new one.

Pre-programmed Power control module costs between $80 to $150, depending on the seller. We always prefer well-renowned third-party sellers. 

Replace Fuel Sending Unit

When the fuel sending unit or gauge sender is faulty, you will see that your Ford F150’s tank is getting empty quickly. Because when there is a problem with the sending unit, it will leak fuel which will eventually cause fuel inefficiency.

Fixing this problem can be challenging for some who don’t have much idea about this problem. Fuel sending unit is expensive, but once it is damaged, you must replace it with a new one. 

It cannot be repaired, so we prefer going to a mechanic, which will cost around 800 bucks with labor costs. You can also follow a service manual to replace it if you are confident.

Repair or Replace Fuel cap and Filler Neck

One of the biggest reasons for fuel leaks is loose fuel caps or cracks. Fuel filler neck that seals the cap can also be faulty, which can cause significant fuel like. As a result, fuel consumption increases drastically.

Solution to this problem with your Ford F150 is to replace the cap and fix or replace the filler neck. It is a straightforward process. Fuel caps are cheap. Depending on quality, you can find caps starting from $8.29 up to $30.

Fuel filler neck also needs to be replaced if there is any problem with that.  It will cost around 50 bucks, and it is easy to replace following a Ford F150 service manual like the previous one.

How To Prevent A P0446 Ford F150 Issue From Happening In The Future

If you want to avoid this situation, you can do it by following some prevention methods against Ford F150’s DTC P0446 issue. Most of it happens by accident or driver’s carelessness. 

We are going to discuss some of prevention methods that can keep your Ford F150 away from P0446 trouble below:

  • EVAP canisters consume a lot of dirty material, so keeping it clean or changing it after a long period is ideal work.
  • Once a week, check the valve circuits. If they are shortened or open, fix them.
  • Vent valves must be clean to keep good airflow. Check the valves once in a while.
  • Run diagnostic with OBD II at least once a month.
  • Check your fuel cap, filler neck, and sending unit, and be aware of any damage.
  • Take your Ford F150 to an expert at least once a month to check the internals.


DTC P0446 issues must be solved as soon as possible because if you don’t fix them, the condition can worsen over time and cause serious damage to your Ford F150. 

You should follow the prevention methods we mentioned above. By following those, you can help yourself by being extra aware of any serious matter before happening.

Some people don’t notice because the symptom is mostly the smell, so check that often. If you want to save yourself from big trouble, take good care of your Ford F150. It will help your vehicle to last longer without any major DTC issues.

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