How To Read Code p0456 Freeze Frame Data Interpretation | Fix It

p0456 dodge is a diagnostic trouble code, the engine control module detects this trouble code when there is a leak in the evaporative emission system of the vehicle while testing. If you will not diagnose this code at the correct time then your engine can also damage.

What is the Evaporative Emission System?

The evaporative emission system of a vehicle prevents the vapors of the fuel from escaping into the environment, it collects and stores these vapors. These fuel vapors will burn in the engine at a suitable time.

The evaporative emission system consists of a charcoal canister which has charcoal to absorb and store the vapors of the fuel, at the time of burning these vapors in the engine fresh air passes through the charcoal canister for retaining the vapors that it is storing, the purge solenoid and valve present in the emission system sucks the fuel vapors into the engine to burn them, the canister vent solenoid and valve help to close this system for checking the leaks present. An evaporative emission system consists of many hoses and valves.

The computer of your vehicle regularly checks for the leaks from this system and whenever the computer detects a leak, it sets the p0456 trouble code. 

Symptoms of p0456 engine code

  • The engine light will start illuminating
  • You will notice a rotten egg smell coming from the engine.
  • The vehicle will become less fuel-efficient.
  • Lacking power from the engine.

Causes of p0456 trouble code

These are some common causes of this trouble code –

  • A defect in purge valve or vent valve
  • Leakage in the evaporative EVAP hose or connector.
  • Gas cap vent or purge vent does not seal properly
  • Leakage in the exhaust system.
  • The gas cap is either loose or damaged.
  • Leakage in the fuel tank of the vehicle.
  • EVAP canister may be leaking.
  • The fuel filler cap is incorrect.

Diagnosing the error 

You can diagnose a trouble code with the help of a code scanner or reader, the EVM detects the trouble and sets the code related to that trouble, and to read that code you need to scan it using a code reader. Always see that you are clearing all the previous DTC codes from the scanner.

EVM can set more than one code, so before fixing trouble dodge engine codes p0456, fix all other troubles also.

Fixing the p0456 engine code

After scanning the trouble code try out these fixes to resolve the problem.

Fix gas cap

One of the common cause of p0456 is a loose or faulty gas cap, so please check the gas cap’s condition first, if it is not good or loose then tighten it and clear the code, but if the gas cap is not loose or you can not see any fault in it then try replacing it with a new one to see it can resolve the issue or not, a gas cap can cost you $20 – $60.

Replace all faulty EVAP hoses:

Check if all the EVAP hoses in the system are in good condition and are working properly, if any of them has cracks it can cause a fault in the system so do replace them and if trouble resolves, clear the code.

Check Charcoal Canister and vent control valve

The charcoal canister is one of the most important parts of the evaporative emission system as it absorbs and stores the vapors of the fuel, so this part must work properly, so check the charcoal canister and look for any damage or leak, if you find something wrong with it replace it with a new charcoal canister, a new charcoal canister can cost you $200-$600 which is quite expensive so do check properly and then do the replacement.

Also, check the charcoal canister vent control valve for the proper functioning and replace it if there is any fault in it, a charcoal canister control valve can cost you $150-$200.

Check Purge volume control valve

The purge volume control valve in the evaporative emission system of your vehicle prevents the fuel vapors in the fuel tank from escaping into the environment and traps them in the charcoal canister. Since you know now that how important it is to keep the vapors of the fuel trapped as it is the most important task of the evaporative emission system, but sometimes this valve can get sticky and cause leaks which will cause them trouble, so to check if it is working properly,

Turn off the power and remove the hoses from both sides of the purge volume control valve and blow air in the openings, if you are unable to blow the air through the openings then the valve is sealed properly otherwise there is a leak somewhere.

If the problem persists then remember that, sometimes it is difficult for you to observe the small leaks, so you have to perform smoke tests to detect these small leaks, you can buy a smoke tester for performing smoke tests online.

Frequently Asked Question

Q1: Will it be safe to drive with an OBD code p0456?

Yes, it is safe to drive with a p0456 engine code but do not drive your vehicle for a long-distance with this trouble and if you are unable to resolve the issue then do take your car to a good mechanic. Driving with a gas leak will also cost you more as the mileage of the vehicle will reduce because of the evaporation of the fuel.

Q2: How to know that the gas cap is not good?

a) If your gas cap is bad then you notice the smell of fuel coming from your vehicle, it normally happens when the gas cap seal is worn-out or it has some damage, a worn-out gas cap leaks the gas from the filler neck.

b) If your gas cap is not tightening properly, or it happens that you tighten the cap and after some time on checking it you notice that it is loose, in such case you have to replace the gas cap or it will cause leaks.

c) Sometimes engine light also blows because of the fault in the gas cap, as it will disturb the functioning of the EVAP system.

Q3: How much will it cost to repair an EVAP leak?

The cost for the labor only would be between $50 and $150, and the other costs will depend on which part needs a replacement, different parts will cost different amounts like a gas cap replacement will be inexpensive while on the other hand replacement of the charcoal canister will cost a good amount of money. The cost will also depend on the quality of the part that you are replacing, as better the quality the more will be the cost.

Q4: The check light of my engine is not turning off, what should I do?

If engine check light is not turning off even after resolving the issue, don’t worry it’s not your mistake because sometimes the computer of your vehicle needs help to see if the issue is resolved or not, so in this case, you have to reset the engine light by following the below techniques:

a) Drive your car normally and the onboard computer will automatically detect there no issue is present now and will turn off the light by itself, if this will not work after driving the car normally for 3 days then it might be possible that the issue exists till yet or you also try other methods.

b) Disconnect the battery of your vehicle and then again connect it, this will clear all the emission data from the vehicle memory.

c) Use a code reader to read the trouble codes and then clear all the codes.

d) Turn on your vehicle for a second then turn off for a second, repeat this 3 times, this will automatically reset the p0456 dodge.

Q5: Is fuel tank gas cap size universal?

Yes, the size of the gas cap is universal in all vehicles but it does not mean that any gas cap can work for all vehicles.

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