Volkswagen Beetle P0455 Code Diagnosis

This is one of the most commonly encountered trouble codes for the Volkswagen Beetle Is the Code P0455. The trouble code refers to a number you receive when your Beetle is plugged into an OBDII scanner. The trouble code P0455 indicates that there are a Leakage large It is part of the evaporative emission controller system. This code is often found with or related to P0420,P0441 and, very frequently, P0440.

The P0455 issue is not usually a threat to your Beetle'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. More information is available at Volkswagen Beetle OBDII Code P0442.

Volkswagen Beetle P0455 Definition

The universal OBDII trouble code P0455 can be used to diagnose any problem. It means that no matter what make or model vehicle you have, this code will always mean the same thing. Technically, the code stands for:

System Gross Leak – Evaporative Emission System

The EVAP captures any fuel vapor in the fuel tank. They are then sent to the intake of the engine to start the combustion process. When there is a large leak in the Volkswagen Beetle’s EVAP system, it will throw the P0455 OBDII Code.

Volkswagen Beetle P0455 OBDII Code Symptoms

The P0455 code is usually not accompanied with any other symptoms than those listed. Smells like gas The service engine soon light. It is possible to notice a slight dip in fuel economy.

Particular attention should be paid to the smell of fuel near the fuel tank or fuel filler tube.

The EVAP system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Beetle P0455 Trouble Code Causes

The P0455 Trouble Code can be triggered in Volkswagen Beetles by many factors. These are some of the more common reasons that the code will be thrown:

• 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 P0455 code. It should be checked for tears or holes. This is one of most frequent causes for the code.
• Vapor Canister Purge Valve– One of the most common causes of the P0455 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.
• The Faulty Charcoal Caister– The charcoal canister is often the cause of P0455.
• Fuel Tank Sending Unit– It is possible for the gasket that attaches the fuel sending unit to the gas tank to go bad. This could cause a drop in tank pressure which can 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. It may be worth your time to get that message and a P0455 to ensure you don't waste any 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.

P0455 Diagnosis- Volkswagen Beetle

To diagnose the problem with your Volkswagen Beetle's P0455, a mechanic can use a variety of tools. The most commonly used methods to diagnose this code are:

• A mechanic will often check for additional 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 P0455, he or she will usually Check out the EVAP System. It includes the purge valve and line as well as the canister.
• A mechanic will examine the gas cap and verify that it is able to withstand high pressure. 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.

Here’s a pretty good video on diagnosing these leaks from Scotty Kilmer, if you are interested:

While the trouble code may state that there is a “large leak” in the EVAP system of your Volkswagen Beetle, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

Most common P0455 fixes

Below are the top P0455 Beetle fixes.

• Replacement of 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 check your gas cap.

It's a good idea to try and figure out why your Volkswagen Beetle is throwing the P0455 code. This should help. You can add any additional information by leaving a comment.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the Beetle’s engine to stop running, it should not be treated lightly. There could be fuel contamination. You should pay extra attention to the level of your fuel tank and ensure that you're not leaking fuel. You should immediately take it in for repair or replacement.