Chevy Cruze P0456: EVAP System – Small Leak

This is one of the most commonly encountered trouble codes for the Chevy Cruze Is the Code P0456. This is the trouble code that you get when you plug in your Cruze to an OBDII scanner. The code P0456 indicates that the evaporative emissions control system has a tiny leak. This code is often found with or related to P0420,P0441 and, very rarely, P0440.

The P0456 problem is not usually a serious threat to your Cruze's driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible.

While the trouble code may state that there is a “small leak” in the EVAP system of your Chevy Cruze, it is actually referring to the amount of pressure lost, and not the physical size of the leak. They can also be very minor.

Chevy Cruze P0456 Definition

The universal OBDII code P0456 can be used to diagnose trouble codes. It means that no matter what make or model vehicle you have, this code will still mean the exact same thing. The code is technically:

System Leakage in the Smallest Detail – Evaporative Emission System

The EVAP system collects fuel vapor from your fuel tank, and then sends it to the intake to ignite the engine in normal combustion. When there is a small leak in the Chevy Cruze’s EVAP system, it will throw the P0456 OBDII Code. If there is a large leak, it’ll throw P0455.

Chevy Cruze P0456 OBDII Code Symptoms

A P0456 Code will not usually be associated with other noticeable symptoms. The smell of gas And the service engine soon light.

The fuel tank and fuel filler tubes should smell particularly strong.

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. But, it won’t affect the way the engine itself runs. The EVAP technology deals only with the fuel vapor but not how the engine runs in the Cruze.

Cruze P0456 Troublecode Causes

Your Chevy Cruze can trigger the P0456 code for trouble. There are many reasons. If your Cruze has warned you at all in the last few months that the fuel cap was off when it wasn’t, then replacing it would be a great first step.

These are some of the most frequent problems that can throw off the code. They're listed in alphabetical order, from the most likely to the least.

• Hose of the Evap System– 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 P0456. You should look for a hole or a tear in the code. This is the main problem that can cause the code.
• Vapor Canister Purge Valve– One of the most common causes of the P0456 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips.
• 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 P0456 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.

P0456 Diagnosis- Chevy Cruze

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Chevy Cruze P0456. The most commonly used methods to diagnose this code are:

• The mechanic will check for 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 P0456. Check out the EVAP System. These include the line and purge valve.
• 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.
• 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:

The Most Popular P0456 Fixes

These are some of the most popular Cruze P0456 fix:

• Replacing the 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 test your gas tank.

We wish you all the best in finding out why your Chevrolet Cruze is throwing the code P0456. We trust this helped. You can add any additional information by leaving a comment.

Do you consider P0456 to be a serious concern?

While P0456 is not going to cause the Cruze’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. Check your tank regularly to make sure there is no fuel leaking. You should immediately take it in for repair or replacement.

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