P0456 Code Jeep Grand Cherokee

p0456 Code Jeep Grand Cherokee: What is it, How to Fix

I was about to drop my children off at school when I noticed the p0456 error code on my Jeep Grand Cherokee.

Fortunately, I was with my mechanic friend.

With his help, we ran a few checks and got it fixed.

In this article, I unravel the p0456 Code Jeep Grand Cherokee, explaining its symptoms, causes, fixes, prevention, and lots more.

What is the p0456 Code Jeep Grand Cherokee?

When you encounter the P0456 code on your Jeep Grand Cherokee, it indicates a small leak in the evaporative emission system, which allows unmetered fuel vapors to escape. This isn’t something to ignore; it’s a sign your Jeep’s trying to communicate about its health.

If your Jeep is a 2014 model and it’s throwing you more than just an emissions code, head over to our article on Problems with 2014 Jeep Cherokee for more insights and troubleshooting tips.

Causes of the p0456 Code Jeep Grand Cherokee

These are the possible causes of the p0456 Code Jeep Grand Cherokee:

  1. Overfilled fuel tank
  2. Faulty EVAP purge valve
  3. Loose gas cap
  4. Damaged EVAP hoses
  5. Contaminated charcoal canister
  6. Capless tanks.

Specific p0456 Code Jeep Grand Cherokee Issues

These are the Specific p0456 Code Jeep Grand Cherokee Issues:

  1. Overfilling the fuel tank: This issue can cause leakage, triggering the error code.
  2. Faulty EVAP purge valve: This is another common cause of the P0456 code.
  3. Loose gas cap: A simple but often overlooked issue that can cause this code.
  4. Damaged EVAP hoses or contaminated charcoal canister: Both can cause leaks in the EVAP system, resulting in the code.

You should also check the Jeep Cherokee Fuse Box Diagram to locate the relevant fuses and circuits.

Symptoms of a P0456 Code

Symptoms of a P0456 Code

These are the Symptoms of a P0456 Code:

  1. Illumination of the check engine light on your dashboard: This is generally the first sign that something is amiss. The engine system has detected a small leak in the evaporative emission control system, signifying the p0456 code Jeep Grand Cherokee issue.
  2. Fuel odor near your vehicle: This is caused by the release of unmetered fuel vapors. This is due to the aforementioned evaporative emission control system leak.
  3. The remote starter function stops working

How to Diagnose P0456 Code

Follow these steps to diagnose P0456 Code:

  1. Smoke Test: By conducting a smoke test on the Evaporative Emission Control System (EVAP), you can easily identify where the system is leaking. This process involves blowing smoke through the system and observing where it escapes.
  2. Check for Loose Connections: Inspect the EVAP system for any loose or disconnected hoses. If you find any, reattach or replace them as necessary.
  3. Inspect the Gas Cap: A loose or damaged gas cap can often trigger the P0456 code. Ensure it’s tightened correctly and isn’t damaged. If it is, replace it.
  4. Scan the Onboard Computer: Use a scan tool to check for any trouble codes stored in the onboard computer. This can provide additional insight into what may be causing the P0456 code.

How to Fix the P0456 Code

How to Fix the P0456 Code

Follow these steps to fix the P0456 code:

  1. You’ll first need to thoroughly diagnose the problem using the methods mentioned previously, which include smoke testing, scanning for trouble codes, and inspecting the EVAP purge valve.
  2. Continue by replacing the faulty gas cap or fuel filler neck if they’re proven defective.
  3. If the issue persists, you may need to replace other components of the EVAP system, like the purge valve or vent valve.
  4. Clear the trouble code from your vehicle’s computer system once you’ve replaced the faulty part.
  5. If the P0456 code persists, consider seeking professional help.

How to Prevent the P0456 Code

Follow these steps to prevent the P0456 Code:

  1. Carefully refuel to avoid overfilling the fuel tank. This is critical for maintaining the pressure balance within the EVAP system. Overfilling the tank can cause pressure build-up and potential leaks.
  2. Ensure you tighten the gas cap properly after refueling. A loose cap can disrupt the sealed EVAP system, potentially triggering the P0456 code.
  3. Regularly inspect your EVAP system components, including the hoses and the charcoal canister. Early detection and addressing any issues can save you from future headaches.
  4. Adhere rigidly to recommended maintenance schedules. Proactive care is a shield against problems that may trigger the P0456 code.
  5. Reach out to a Jeep dealer for additional support. Their expert knowledge can be invaluable in maintaining your vehicle and resolving potential EVAP system issues.

Got a 2015 Jeep Cherokee? Head over to our 2015 Jeep Cherokee Transmission Problems guide for helpful tips on preventing another unwelcome surprise!

When to Consult a Professional

When to Consult a Professional

If the P0456 code reappears after you’ve cleared it using an OBDII scanner, it’s a clear sign that a deeper issue might be at play. A professional can diagnose and address this recurring problem accurately.

The P0456 code Jeep Grand Cherokee repair methods can sometimes be challenging. If you find them beyond your expertise, don’t hesitate to seek professional help.

Similarly, if your remote starter stops functioning after the P0456 code is triggered, a professional technician can help troubleshoot and resolve this issue.

Likewise, when considering a PCM reflash or software update related to the P0456 code, it’s crucial to consult a professional. These procedures need accurate execution to ensure your Jeep’s software version is correct and operates optimally.

Lastly, if you encounter difficulties in replacing the ESIM module in a 2018 model, a professional mechanic’s assistance is invaluable to avoid potential damage.

Diagnosis Costs

When it comes to diagnosing a P0456 code with your Jeep Grand Cherokee, you’ll find that costs can vary.

It typically ranges from $100 to $200 depending on the complexity of the issue and the service provider. Here are some factors to consider:

Repair and Maintenance

Dealing with a P0456 code on your Jeep Grand Cherokee involves understanding the repair and maintenance costs as well as other considerations that can influence these expenses.

You’ll need to account for the diagnosis, which could range from $50 to $150.

Then, there’s the cost of parts and labor. This can vary widely, depending on whether the issue is a simple faulty gas cap or a more complex evaporative emissions system fault. Factors like your vehicle’s age and model can also impact repair costs.

Regular maintenance checks can help prevent this issue. It’s also advisable to replace the gas cap regularly as a preventative measure.

Frequently Asked Questions

These are the frequently asked questions on p0456 Code Jeep Grand Cherokee:

How Do I Fix Code P0456?

You’ll need to follow troubleshooting steps to fix code P0456. Start by inspecting the gas cap, then check the EVAP system for leaks. If that doesn’t work, professional repair might be necessary.

Can You Still Drive With a P0456 Code?

Yes, you can still drive. Like carrying an extra load, it won’t affect immediate performance. However, it’s important to address the code implications soon, as ignoring it could lead to other complications later.

How Much Does It Cost to Fix P0456?

In terms of repair expenses, fixing a P0456 code can range widely. You could pay as little as $20 for a new gas cap, or over $500 for major component replacements. It’s variable.


In conclusion, the P0456 code in your Jeep Grand Cherokee is like a small cry for help from your EVAP system. Don’t turn a deaf ear. Heed its call by diagnosing and fixing the issue promptly.

Keep an eye on your fuel levels, valves, and hoses, and remember that prevention beats cure. If the code persists, don’t hesitate to bring in a professional. The cost may be a bitter pill to swallow, but it’s better than risking further damage.

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