Dodge Caravan P0456: EVAP System – Small Leak

This is one of the most commonly encountered trouble codes for the Dodge Caravan The Code P0456. The trouble code refers to a number you receive when your Caravan is plugged into an a 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 threat to your Caravan'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 Dodge Caravan, it is actually referring to the amount of pressure lost, and not the physical size of the leak. They can also be very minor.

Dodge Caravan 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 always mean the same (Caravan and not). Technically, the code stands for:

System Leakage of Small Size – Evaporative Emission System

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

Dodge Caravan P0456 OBDII Code Symptoms

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

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

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 system is for fuel vapor and does not affect the operation of your Caravan's engine.

Caravan P0456 Trouble Code Causes

P0456 can be triggered by many factors in your Dodge Caravan. If your Caravan 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.

Below are the top most probable problems that could throw the code. These were listed alphabetically, in some order.

• 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 P0456 error code will be generated. You should look for a hole or a tear in the code. This is the leading cause of 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. 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 P0456. 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.

P0456 Diagnosis- Dodge Caravan

To diagnose the problem with your Dodge Caravan's P0456, a mechanic can use a variety of tools. The most commonly used methods to diagnose this code are:

• The mechanic will 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.
• The mechanic will normally determine what trouble codes are associated with P0456. 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:

The Most Popular P0456 Fixes

Below are the top Caravan P0456 fixes.

• 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 test your gas tank.

It's a good idea to try and figure out why your Dodge Caravan is throwing the code P0456. This should help. 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 Caravan’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. It is best to have it checked and/or dealt with immediately.

Feel free to add anything to the article by leaving a comment. Thanks!