Truck owners across the country face a serious issue. Many Chevrolet Silverado and GMC Sierra diesel trucks come with a part that can fail without warning. That part is the CP4 fuel pump. This small but powerful engine piece can cause major damage. Owners have reported broken pumps, costly repairs, and engine failures.
Now, the problem has reached court. A class action lawsuit against General Motors (GM) led to a major settlement. Silverado and Sierra owners with specific diesel models may qualify. The lawsuit claims the CP4 fuel pump was not made for American diesel fuel. As a result, it breaks too easily and harms the whole engine.
This case affects thousands of truck owners. Many people do not even know they qualify for payment or repair help. If you own or once owned a Silverado or Sierra diesel truck, you may have rights. This guide explains the lawsuit in simple terms. It shows who qualifies, how to file a claim, and what owners can expect.
You do not need legal training to understand this post. You just need clear facts. Read on to see what the lawsuit means and what steps you can take.
What Is the CP4 Fuel Pump?
The CP4 fuel pump is a high-pressure part. Bosch made this pump to meet diesel engine needs. GM added it to Silverado and Sierra diesel trucks between 2011 and 2016. The CP4 takes fuel from the tank and pushes it into the engine with force.
In theory, the pump should improve power and fuel use. In real life, it does not match U.S. diesel quality. American diesel fuel has less lubrication than European fuel. The CP4 needs more lubrication to work right. Without it, the pump can grind itself down.
Once the pump breaks, metal parts spread into the fuel system. This can cause full engine failure. Repairs often cost over $10,000. The damage can hit injectors, filters, lines, and the engine itself.
What the Lawsuit Claims
The class action lawsuit claims GM knew about the problem. It says GM still sold the trucks with the same pump. The lawsuit also says GM should have warned buyers or offered safer parts. Instead, many people paid for repairs out of pocket. Some had the truck break down with little warning.
The lawsuit covers Chevrolet Silverado and GMC Sierra trucks with the 6.6L Duramax diesel engine. These trucks used the CP4 fuel pump and faced high risk of failure.
A federal judge approved the settlement in 2025. GM agreed to pay up to $50 million to fix or repay truck owners. The settlement does not mean GM admits guilt. It means the case closed with a deal to help drivers.
How to Find the Best Traffic Lawyer Near You
Who Qualifies for Compensation?
Not all Silverado and Sierra owners qualify. The lawsuit only covers certain models and locations. To be part of the case, you must meet the following rules:
- You bought or leased a 2011–2016 Silverado or Sierra
- Your truck has a 6.6L Duramax diesel engine (LML)
- You bought the truck from a GM dealer
- You lived in California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas at the time
The purchase or lease must have occurred between March 1, 2010 and September 13, 2024. If you owned more than one truck that meets the rules, you may file more than one claim.
How Much Can You Get?
The payment depends on what happened with your truck. The settlement gives money for repairs, offers smaller amounts to past owners, and adds limited warranty help.
If you paid to fix the CP4 fuel pump, you may get all your money back. This includes cost of parts, labor, and damage from the pump. Most owners may get between $6,300 and $12,700.
If you sold the truck without fixing it, you may get $400 to $800.
If you still own the truck, GM may cover half the cost of new repairs. This only applies to work done at GM dealers between May 6, 2025 and May 6, 2026, or before the truck hits 200,000 miles.
You must show proof. Keep repair bills, sale papers, or title records. You will need these when you send your claim.
How to File a Claim
To get payment or warranty support, you must file a claim. The official settlement website is:
You can check your VIN on the site to see if your truck qualifies. The VIN is a 17-digit number found on your dashboard or vehicle documents.
The deadline to file your claim is November 6, 2025. Claims must include:
- A completed claim form
- Proof of ownership or lease
- Proof of repair or sale (if needed)
- Truck’s VIN
You can file online or by mail. If you miss the deadline, you may lose your chance to receive anything.
Why the CP4 Issue Matters
This case is not just about one broken part. It shows what happens when a design does not match real use. The CP4 fuel pump worked in Europe, but not in the U.S. GM still used it without proper change. As a result, owners faced major bills and engine loss.
The lawsuit pushed GM to take action. The settlement may help some drivers recover costs. Still, it came too late for others who sold their trucks after major damage.
If you have a truck at risk, do not wait. Check your eligibility. File your claim. Protect your rights.
What to Do After Filing
After you file, watch your mail and email. The claims team may ask for more documents. If your claim gets approved, you will get payment or repair help based on your case.
Keep your truck in good condition. Use clean diesel fuel. Change filters on time. If you face pump failure in the future, the repair warranty may help.
Stay updated. The website will post any new details. If a second settlement happens, past claimants may get more help.
Frequently Asked Questions
| Question | Answer |
|---|---|
| What is the CP4 fuel pump lawsuit about? | The lawsuit claims GM used a faulty CP4 fuel pump in Silverado and Sierra trucks that can cause engine failure. |
| Which trucks are included in the lawsuit? | The lawsuit covers 2011–2016 Chevrolet Silverado and GMC Sierra trucks with a 6.6L Duramax diesel engine (LML). |
| Do I need to live in a certain state? | Yes. You must have bought or leased the truck in CA, FL, IL, IA, NY, PA, or TX to qualify. |
| What can I get from the settlement? | You may get full repair cost reimbursement, a partial warranty, or $400–$800 if you sold the truck without fixing it. |
| What is the deadline to file a claim? | The deadline is November 6, 2025. Claims after this date may not get accepted. |
| How do I file a claim? | Go to gmfuelpumplitigation.com, check your VIN, and submit the required forms and proof. |
| What documents do I need? | You need proof of ownership, repair receipts (if any), and your truck’s VIN. |
| What if I do not have repair receipts? | You may still get a small payment as a past owner if the truck qualifies and you provide proof of sale. |
| Will I get money if I no longer own the truck? | Yes, if you meet the other rules. You may get a smaller payment without proof of repair. |
| Can I still get help if my truck breaks later? | If you still own the truck, you may qualify for 50% repair cost coverage through May 6, 2026. |
Conclusion
The CP4 fuel pump lawsuit brings some justice to Silverado and Sierra owners. It shows the power of collective action. Drivers stood up and demanded answers. Now they have a path to recover what they lost.
If you bought or leased a 2011-2016 Silverado or Sierra diesel truck, check your rights. Use the official site to file a claim before the deadline. You may be owed money, repairs, or both.
This issue is more than fuel pumps. It is about trust and fair treatment. Know the facts. Take action. Help others by sharing this guide with fellow truck owners.
To see how other buyers faced losses in a different lawsuit, read our post on the Dapper Development lawsuit.
Please Note: This article shares general legal facts. It does not offer legal advice. It does not form any attorney-client link. Speak to a licensed lawyer about your case before you act.