Mercury Mariner P0446: EVAP Vent Control Circuit → Malfunction
The most frequent trouble code with the Mercury Mariner Is the Code P0446. The trouble code refers to a number you receive when your Mariner is plugged into an OBDII scanner. It indicates that an error has occurred in the evaporative emission controller system. This code is often found with P0440, P0441 or P0440.
P0446: Evaporative Emission Control System → Vent Control Circuit → Malfunction
Normally, P0446 does not pose a threat to vehicle 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.
Mercury Mariner P0446 OBDII Symptoms
Most commonly, the P0446 code does not cause any symptoms. You will see the light on your service engine shortly, but this is typically it. It is possible to notice an increase in fuel consumption, but it is unlikely. A slight gas smell may be caused by P0446. It is related to fuel vapors.
Mercury Mariner P0446 Significance
P0446 stands for a universal OBDII Trouble Code. 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 captures any fuel vapor in the fuel tank, and transmits it 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.
Mariner P0446 Trouble code Causes
You can have the Mercury Mariner's P0446 trouble code trigger. The most frequent problems that trigger this code are:
- 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. This can lead to the code P0446. You should look for a hole or a tear in the fabric.
- 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. This could cause line pressure to drop and throw 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. 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 Mercury Mariner Diagnosis
To diagnose the problem with your Mercury Mariner's P0446, a mechanic can use a variety of tools. These are some of the common diagnostics that can be done for the code
- A mechanic will often 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.
- 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.
- Monitoring and checking the fuel tank pressure is a must.
- Following the inspections and repairs, the mechanic will conduct two more tests.
- A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.
Most common P0446 fixes
Below are the top Mariner P0446 solutions:
- Replacing the gas cap
- Replacement for EVAP Line
- Replace charcoal canister
- Change the fuel tank
It is best to begin with the gas cap, and then work your way up to the fuel tanks. The gas cap is the most difficult and cost-effective item to replace.
Here’s a great video on How to check your gas cap.
It's a good idea to try and figure out why your Mercury Mariner is throwing the P0446 codes. We trust this helped. Please leave us a comment below if you have any suggestions. Enjoy your day.
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