Toyota Celica P0446: EVAP Vent Control Circuit → Malfunction

This is one of the most commonly encountered trouble codes for the Toyota Celica Is the Code P0446. This trouble code is the number given to you by an OBDII scanner when you connect your Celica. It indicates an error in the evaporative emission controller system. This code is often found with P0420 or P0441 codes.

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.

Toyota Celica P0446 OBDII Code Symptoms

Most commonly, the P0446 code does not cause any 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 smell after using P0446. Because it is related to the fuel vapors system, P0446 may also cause a slight gas smell.

Toyota Celica P0446 Meaning

The universal OBDII code P0446 can be used to diagnose trouble codes. The code can be used regardless of the make and model of the vehicle. Technically, the code stands for:

Evaporative Emission Control System Vent Control Circuit Malfunction

The EVAP system collects fuel vapor from fuel tanks and then sends it to the intake of the engine to ignite the normal combustion process. 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.

Celica P0446 Trouble Code Causes

P0446 can trigger your Toyota Celica's trouble code. These are some of the more common issues that can trigger the P0446 trouble code in your Toyota Celica.

• 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. There are some clips you will need to look for and then remove.
• EVAP Hose– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. The P0446 code will be generated. 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.
• 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.

P0446 Diagnoses- Toyota Celica

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Toyota Celica P0446. 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 Take a look at 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

Below are the top Celica P0446 solutions:

• Replacing the gas cap
• Replacement for EVAP Line
• Replace charcoal canister
• Replacing 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 test your gas tank.

You will need to solve the problem quickly. This should help. Please leave us a comment below if you have any suggestions. Enjoy your day.