Fiat 500 P0455 code Diagnosis

The most frequent trouble code with the Fiat 500 Is the P0455 Code. The trouble code refers to a number you receive when your 500 is plugged into an OBDII scanner. If there's a problem, P0455 means that it is. 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.

Your 500's driveability is usually not affected by P0455. 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 with P0442. More information is available at Fiat 500 OBDII Code P0442.

Fiat 500 P0455 Definition

The universal OBDII code P0455 can be used to diagnose trouble codes. The code can be used regardless of the make and model of the vehicle. The code is technically:

System Gross Leak – Evaporative Emission System

The EVAP system collects fuel vapor from fuel tanks and then sends it to the intake of the engine to ignite the combustion process. When there is a large leak in the Fiat 500’s EVAP system, it will throw the P0455 OBDII Code.

Fiat 500 OBDII code Symptoms

A P0455 Code will usually not cause any symptoms except the ones listed below. The smell of gas And the service engine soon light. The slightest drop in fuel economy may also be noticeable.

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

The EVAP process deals with fuel vapors directly. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

500 Trouble codes P0455

Many things can trigger the Fiat 500's P0455 code. The most frequent problems that trigger this code are:

• Hose of the Evap System– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. The P0455 error code will be generated. 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. It can lower the tank pressure, which could throw out 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 P0455. 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.

P0455 Fiat 500 Diagnosis

To diagnose the problem with your Fiat 500's P0455, a mechanic can use a variety of tools. The most commonly used methods to diagnose this code are:

• The mechanic will usually check for any additional trouble 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 P0455, he or she will usually Check out the EVAP System. It includes the line, purge valve and 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.
• 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.

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 Fiat 500, 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 500 most popular P0455 fixes.

• Replacing the gas cap
• Replacing EVAP lines
• 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 cap can be replaced the most easily and cheaply.

Here’s a great video on How to test your gas tank.

You will need to find the cause of Fiat 500 throwing the P0455 code. This should help. Please feel free to add anything below.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the 500’s engine to stop running, it should not be treated lightly. There could be fuel contamination. Check your tank regularly to make sure there is no fuel leaking. You should immediately take it in for repair or replacement.