Ford Focus P0446: EVAP Vent Control Circuit → Malfunction

This is one of the most commonly encountered trouble codes for the Ford Focus Is the Code P0446. The Trouble Code refers to a number given when your Focus is plugged in to an OBDII scanner. The code P0446 indicates that the evaporative emissions control system is failing. You may see it along with the following codes: 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. This is usually accompanied by P0442. Another common code for trouble is P0420. It often comes with P0446.

Ford Focus 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. It is possible to notice an increase in fuel consumption, but it is unlikely. You may notice a gas smell after using P0446. Because it is related to the fuel vapor system, P0446 may also cause a slight gas smell.

Ford Focus P0446 Meaning

The universal OBDII code P0446 can be used to diagnose any problem. It means that no matter what make or model vehicle you have, this code can mean the exact same thing (Focus). 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. The EVAP control control circuit will not respond to an ECU if it detects a problem with the vent control circuit. This will cause the engine's service light to illuminate and throw the OBDII P0446 code.

Focus P0446 Trouble code Causes

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

• 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. You should look for a hole or a tear in the fabric.
• A Faulty Canister of Charcoal– 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.
• Fuel Cap– 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. It may be worth your time to get that message and a P0446 to check if the fuel cap is working.
• 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 Focus Diagnosis - Part 0446

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Ford Focus P0446. These are some of the common diagnostics that can be done for the P0446 code.

• The mechanic will check to make sure there are no other codes. It is easier to diagnose problems if there are more codes. 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.
• The mechanic will normally determine what trouble codes are associated with P0446. 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 most popular Focus 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 Focus throwing the code P0446. This should help. Feel free to add anything below. Enjoy your day.