Picture this. You are driving your 2013 GMC Sierra 2500HD on the highway, hauling a trailer, minding your own business. Suddenly the engine sputters. Power drops. The truck rolls to a dead stop on the shoulder. You call a mechanic, and two days later you get the call — the high-pressure fuel pump has failed. The entire fuel system is contaminated with metal shavings. The repair bill? Just over $12,000.
This is not a one-off story. This happened to thousands of Silverado and Sierra owners across the United States. And it is exactly the kind of nightmare that led to the cp4 fuel pump silverado sierra lawsuit — one of the most significant diesel truck class action cases in American automotive history.
If you own or previously owned a 2011–2016 Chevrolet Silverado or GMC Sierra with a 6.6L Duramax diesel engine, you need to read every word of this article. There is money on the table, but the deadline to claim it is real.
What Is the CP4 Fuel Pump and Why Did GM Install It?
Before diving into the lawsuit itself, it helps to understand what the CP4 actually is — and why it became such a problem.
The Bosch CP4 is a high-pressure fuel injection pump. It is responsible for pushing diesel fuel from the tank into the common rail at extremely high pressures, sometimes exceeding 26,000 PSI. That pressure is what makes modern diesel engines so efficient and powerful. Without a working pump, the engine gets nothing.
GM introduced the CP4 into its 6.6L Duramax LML engine starting with the 2011 model year. The goal was straightforward — better fuel efficiency, lower emissions, and reduced production costs. The CP4 replaced the older CP3 pump, which had a stronger internal design but was considered less efficient for modern emissions standards.
Here is where the problem starts. The CP4 was engineered primarily for the European diesel market. European diesel fuel contains higher lubricity — meaning it is slicker, more lubricating — than the ultra-low sulfur diesel (ULSD) sold at American fuel stations. ULSD was introduced in the U.S. as an environmental measure to reduce sulfur emissions. It is cleaner for the environment, but it is also significantly less lubricating than the diesel the CP4 was designed to run on.
The CP4 pump relies on the diesel fuel itself to lubricate its internal moving parts. When that fuel does not provide enough lubrication, the internal components — particularly the roller tappets and drive cam — begin experiencing metal-on-metal friction. That friction generates heat, accelerates wear, and eventually causes catastrophic internal failure.
GM knew this pump was going into American trucks that would be filled with American diesel. The mismatch between the pump’s design requirements and the fuel it would actually run on is central to the entire legal argument behind the cp4 fuel pump silverado sierra lawsuit.
How the CP4 Fails: The Chain Reaction That Destroys Your Engine
The CP4 does not fail quietly or gradually. When it goes, it goes all at once, and it takes the rest of the fuel system with it.
Here is how the failure unfolds inside your engine.
Stage One — Lubricity Starvation
American ULSD falls below the lubricity levels the CP4 needs to function safely. The internal roller-tappet mechanism begins experiencing friction instead of smooth rolling contact. The follower skips and skids across the cam lobe instead of rotating properly.
Stage Two — Internal Wear Begins
Metal begins grinding against metal inside the pump housing. The drive cam and pistons start shedding microscopic metal particles. These particles mix directly into the fuel supply.
Stage Three — Contamination Spreads
There is no internal filter inside the CP4 to catch debris. Metal shavings flow from the pump directly into the high-pressure fuel rail, into the injectors, through the fuel lines, and back into the tank. Everything downstream gets contaminated at once.
Stage Four — Total System Failure
The injectors seize. The fuel rail is compromised. In some cases, parts of the pump housing physically crack. The engine cranks but cannot start. When the tow truck arrives, the damage is already done everywhere. The repair is not just replacing a pump. Owners have faced full fuel system replacements — injectors, fuel rail, pump, fuel lines, and in severe cases the tank itself. That is where repair bills between $10,000 and $15,000 come from.
Warning Signs to Watch For
If you still have a qualifying truck and the pump has not yet failed, these are the early warning signs to take seriously.
- Unexpected engine stalling, especially when accelerating or under load
- Hard starting, particularly in cold temperatures
- Noticeable loss of power while driving
- Check engine light activation related to fuel pressure codes
- Rough idle or misfiring that was not there before
- Increased fuel consumption without any change in driving habits
The dangerous reality is that many CP4 failures happen with almost no warning at all. A truck can run perfectly fine one day and be dead the next.
The CP4 Fuel Pump Silverado Sierra Lawsuit: How It All Started
The legal story behind the cp4 fuel pump silverado sierra lawsuit begins not with attorneys, but with ordinary truck owners who started comparing notes.
Around 2016, GM quietly issued Technical Service Bulletin TSB 16-NA-102 to its dealerships. This bulletin acknowledged problems related to CP4 pump failures in Duramax diesel trucks. What it did not do was notify truck owners directly, offer any kind of proactive repair or recall, or acknowledge that the root cause was a fundamental design incompatibility with American fuel.
Owners continued experiencing failures. Some had them covered under warranty. Many did not. As time passed and trucks aged past their warranty periods, the out-of-pocket repair bills started piling up. Online forums filled with stories that all sounded the same — sudden failure, metal shavings, astronomical repair costs, and a GM dealership that had little to offer.
In 2019, the master lawsuit was formally filed in federal court in Michigan. The case, Chapman v. General Motors LLC (Case No. 2:19-cv-12333-TGB-DRG), was assigned to Judge Terrence G. Berg. It alleged that GM knew the CP4 pump was incompatible with U.S. diesel fuel standards and sold trucks with this defect while failing to disclose the known risk to buyers.
Several related lawsuits were also filed around the same time, including cases naming Bosch — the pump manufacturer — as a defendant. These included Berry v. Robert Bosch, Click v. GM, Hockensmith v. Robert Bosch, Martinez v. Robert Bosch, Moonan v. General Motors, and Ginebra v. General Motors. By May 2020, these cases were consolidated into a single coordinated class action proceeding.
The central legal argument was straightforward but powerful. GM did not simply sell a truck with a part that wore out. GM sold a truck with a part that was fundamentally incompatible with the fuel that American owners would logically and inevitably put in it — and GM did not tell them. Plaintiffs argued this violated state consumer protection laws and warranty obligations. GM denied wrongdoing, but the litigation continued to grow.
CP4 Fuel Pump Silverado Sierra Lawsuit Update: The 2025 Settlement You Need to Know
This section covers the most important development for Silverado and Sierra owners — the final settlement that resolved the cp4 fuel pump silverado sierra lawsuit in 2025.
After years of litigation and discovery, GM agreed to a settlement in principle in 2024. The court held final review in January 2025, and on May 6, 2025, Judge Terrence G. Berg granted final approval to the settlement agreement.
The Settlement Fund
GM agreed to establish a $50 million settlement fund. Within that total, approximately $30 million is designated specifically as a repair fund for class members who paid out of pocket for CP4-related repairs. This is real money going directly to truck owners who bore the financial burden of GM’s defective pump.
Future Repair Reimbursement
Beyond past repairs, the settlement also includes a future repair provision. Owners who have CP4 pump repairs performed at a GM-authorized dealership on or after May 6, 2025, can receive 50 percent cash back on those repairs. This reimbursement is available until May 6, 2026, or until the vehicle reaches 200,000 odometer miles — whichever comes first. Claims for future repairs must be submitted within 60 days of receiving the repair invoice.
GM’s Position
It is worth noting that GM settled without admitting liability. The company maintains it did nothing wrong but chose to resolve the litigation to avoid the cost and uncertainty of continued legal proceedings. This is a common posture in class action settlements and does not reduce the validity of the compensation available to qualifying owners.
This cp4 fuel pump silverado sierra lawsuit settlement update represents the culmination of years of legal effort by thousands of affected truck owners. Do not miss your window.
Which Trucks Are Covered: Full Eligibility Breakdown
Not every Silverado or Sierra owner qualifies for this settlement. Understanding the eligibility rules clearly is critical before you invest time in filing a claim.
Qualifying Vehicles
The settlement covers 2011–2016 Chevrolet Silverado 2500HD and 3500HD trucks, and 2011–2016 GMC Sierra 2500HD and 3500HD trucks, equipped with the 6.6L Duramax LML diesel engine and the Bosch CP4 high-pressure fuel pump. Not all Silverado and Sierra trucks from these years had the CP4. Only those with the LML engine variant are covered.
You can verify your engine type by checking the eighth character of your Vehicle Identification Number (VIN). For LML engines, that character will be an “8.” You can also check your owner’s documentation or ask a dealership to confirm.
Purchase Window and States
The truck must have been purchased from a GM-authorized dealership between March 1, 2010, and September 13, 2024. Critically, the purchase must have taken place in one of these seven states: California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas.
If your truck was purchased in another state, you may not be covered under this particular settlement. However, other legal proceedings related to CP4 failures are ongoing in additional jurisdictions, so it is worth consulting with a consumer attorney if you are outside these seven states.
Who Qualifies for What
Current owners who experienced CP4-related failures and paid for repairs out of pocket can file for reimbursement. Former owners who no longer have the truck but paid for qualifying repairs also qualify. The reimbursement amount for past repairs will depend on how many total valid claims are submitted — the $30 million repair fund is divided among all qualifying claimants.
Who Is Excluded
Owners who already settled their claim individually with GM are excluded. GM employees and the presiding judge are also excluded. Additionally, any vehicle that was modified to use an aftermarket fuel system is not eligible, as the modification makes it difficult to attribute damage specifically to the factory CP4 defect.
How to File Your Claim: Step-by-Step
Filing a claim in the cp4 fuel pump silverado sierra lawsuit settlement is straightforward if you have the right documents ready. Here is exactly what you need to do.
Step One — Confirm Your Eligibility
Go to GMFuelPumpLitigation.com and enter your VIN. The system will tell you whether your vehicle falls within the covered class. Do this first, before gathering any documents, to avoid wasting time.
Step Two — Gather Your Documentation
You will need three types of documents depending on your situation.
For proof of purchase, you need dealer purchase documents that clearly show your name, the selling dealer, the vehicle, and the purchase date. A signed purchase agreement or bill of sale works well.
For proof of repair, you need repair invoices or payment records that specifically identify the CP4 high-pressure fuel pump or related components. Ideally these records will reference GM TSB 16-NA-102 or describe metal contamination in the fuel system. Invoices from GM dealerships are strongest, but independent repair shop invoices are acceptable if they are sufficiently detailed.
For former owners, you also need proof of sale — documents showing the date you sold the vehicle, the VIN, and both buyer and seller information.
Step Three — Submit Your Claim
Submit everything through GMFuelPumpLitigation.com before the deadline. The claim deadline for past repairs and former owner claims is November 6, 2025. Future repair claims must be submitted within 60 days of the repair date.
Step Four — Wait for Processing
Once submitted, the settlement administrator reviews your claim, verifies documentation, and approves or denies it. Approved claims will be paid after all appeals are resolved. If you have questions about your specific situation, the settlement website has contact information for the administrator. You can also consult a consumer protection attorney for guidance.
Protecting Your Diesel Going Forward
Whether or not you qualify for this settlement, if you own a diesel truck with a CP4 pump — Duramax or otherwise — there are practical steps you should take right now to protect your engine.
Use a Quality Fuel Lubricity Additive
This is the single most impactful preventive measure. A good diesel fuel lubricity additive, added at every fill-up, compensates for the lower lubricity of American ULSD. Look for additives that specifically list lubricity improvement as a primary function. Not all diesel additives are created equal — some focus on cetane boost or injector cleaning. You want lubricity improvement above all else.
Never Run Your Tank Low
Running the fuel tank below a quarter tank increases the risk of air entering the fuel supply. Air in the fuel line means metal-on-metal contact inside the CP4, even if the fuel itself has adequate lubricity. Keep the tank at least one-quarter full at all times.
Consider a CP3 Conversion
The older CP3 pump design is internally more robust than the CP4. It was not as sensitive to ULSD lubricity levels, and it does not suffer from the same catastrophic failure mode. Many diesel enthusiasts and performance shops offer CP3 conversion kits for LML Duramax engines. If you plan to keep your truck long-term, this upgrade is worth serious consideration.
Know the Broader Picture
The CP4 problem is not unique to GM. Ford’s 6.7L Power Stroke diesel engines from 2011 onward also used the CP4, and a separate class action litigation against Ford has been developing in parallel. The cp4 fuel pump silverado sierra lawsuit outcome sends a clear message to automakers: installing components fundamentally mismatched with the operating conditions of your market — and failing to disclose that — will result in legal consequences. It is a precedent that benefits all diesel truck owners, not just those who drove Silverados and Sierras.
Frequently Asked Questions About the CP4 Fuel Pump Silverado Sierra Lawsuit
1. What is the cp4 fuel pump silverado sierra lawsuit about?
The cp4 fuel pump silverado sierra lawsuit is a class action legal case against General Motors alleging that the Bosch CP4 high-pressure diesel fuel pumps installed in 2011–2016 Silverado and Sierra HD trucks were incompatible with American ultra-low sulfur diesel fuel, leading to catastrophic failures and costly repairs that GM failed to disclose to buyers.
2. How much is the settlement worth in the cp4 fuel pump silverado sierra lawsuit?
GM agreed to a $50 million settlement fund, with approximately $30 million specifically designated for reimbursing class members who paid out of pocket for CP4-related fuel system repairs. The remaining funds cover future repair reimbursements, administrative costs, and attorney fees.
3. Which trucks are eligible for the cp4 fuel pump silverado sierra lawsuit settlement?
Eligible trucks are 2011–2016 Chevrolet Silverado 2500HD and GMC Sierra 2500HD models equipped with the 6.6L Duramax LML diesel engine. The vehicle must have been purchased from a GM-authorized dealer in California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas between March 1, 2010, and September 13, 2024.
4. Can I still file a claim if I no longer own the truck?
Yes. Former owners who paid for qualifying CP4 repairs out of pocket are still eligible to file a claim. You will need proof of ownership, proof of the repair, and documentation showing the sale of the vehicle.
5. What is the deadline to file a claim in the cp4 fuel pump silverado sierra lawsuit?
The deadline for past repair reimbursement claims and former owner claims is November 6, 2025. Future repair reimbursement claims must be submitted within 60 days of the repair and are available until May 6, 2026, or until the vehicle reaches 200,000 miles.
6. How do I know if my Silverado or Sierra has the CP4 pump?
Check the eighth digit of your Vehicle Identification Number. An “8” in that position indicates a 6.6L LML Duramax engine, which is the engine paired with the Bosch CP4 pump covered by this settlement. You can also verify directly on the official settlement website by entering your VIN.
7. Did GM admit wrongdoing in the cp4 fuel pump silverado sierra lawsuit settlement?
No. GM agreed to settle the lawsuit without admitting any liability or wrongdoing. This is a standard practice in class action settlements, as it allows the company to resolve the case while avoiding the unpredictability of a jury verdict.
8. How much money will individual claimants receive?
The exact payout per claimant depends on how many valid claims are submitted. Reports suggest some claimants could receive up to $12,712 for documented repair costs, though the actual amount will be proportional to the total number of valid claims filed against the $30 million repair fund.
9. What documents do I need to file a claim?
You need proof of purchase from a GM dealership, proof of payment for CP4-related repairs — invoices identifying the high-pressure fuel pump or components referenced in GM TSB 16-NA-102 — and for former owners, documentation showing the sale of the vehicle.
10. Does the cp4 fuel pump silverado sierra lawsuit cover Ford trucks too?
This specific settlement covers only GM vehicles — Chevrolet Silverado and GMC Sierra with the LML Duramax engine. However, separate class action litigation involving the CP4 pump in Ford Power Stroke diesel trucks has also been filed and is proceeding independently.
Conclusion
The cp4 fuel pump silverado sierra lawsuit is more than a legal settlement. It is the documented story of tens of thousands of truck owners who bought vehicles they trusted, filled them with the only fuel available at American pump stations, and were left with five-figure repair bills through no fault of their own.
General Motors issued a $50 million settlement — now final as of May 6, 2025 — that acknowledges the scale of harm these CP4 pump failures caused. Whether you are a current owner who paid for repairs, a former owner who sold a damaged truck at a loss, or someone still driving a qualifying vehicle and looking for future repair relief, the claim process is available to you.
But you need to act before November 6, 2025.
Check your VIN, gather your repair invoices, and file your claim at GMFuelPumpLitigation.com today. Do not leave money on the table because you waited too long to read the fine print.
Q1. What is the CP4 fuel pump Silverado Sierra lawsuit about?
The lawsuit alleges that the Bosch CP4 high-pressure fuel pumps installed in certain Chevrolet Silverado and GMC Sierra diesel trucks are not compatible with U.S. diesel fuel and are prone to catastrophic failure, often requiring costly repairs and potentially damaging the engine. Plaintiffs argued that GM failed to disclose this design defect, violating state consumer protection and warranty laws. GM denied wrongdoing but agreed to settle to avoid continued litigation.
Q2. Which trucks are covered in the CP4 fuel pump Silverado Sierra lawsuit?
The settlement covers owners of 2011–2016 Chevrolet Silverado and 2011–2016 GMC Sierra diesel trucks purchased from a GM dealership between March 1, 2010, and September 13, 2024. The diesel truck must be equipped with a 6.6L Duramax engine and Bosch CP4 high-pressure diesel fuel pump. Only 2500HD and 3500HD heavy-duty variants with the LML engine variant are included.
Q3. How much can I get from the CP4 fuel pump Silverado Sierra lawsuit settlement?
Payouts are estimated to range between $6,356 and $12,712 per vehicle depending on the number of valid claims filed by the November 2025 deadline. This is intended to cover a significant portion of the total system replacement these failures require. Former owners who no longer own their truck may receive smaller payments, typically ranging from $400 to $800, intended to compensate for the diminished value of a truck equipped with a known faulty component.
Q4. How much total did GM agree to pay in the CP4 fuel pump lawsuit settlement?
The settlement provides a $50 million fund, with $30 million specifically allocated to compensating class members who paid out of pocket for a repair of their high-pressure fuel pump. The settlement also provides for partial cash back for future repairs for CP4 fuel pump replacements and repairs performed on or after May 6, 2025, at GM-authorized dealerships. The remaining funds cover attorney fees, administrative costs, and former owner compensation.
Q5. What is the deadline to file a claim in the CP4 fuel pump Silverado Sierra lawsuit?
The statute of limitations means you must not miss the deadline. If you do, you will be ineligible for the settlement funds. Additionally, this would automatically exclude you from getting any reimbursement for future repairs. The final settlement approval was granted on May 6, 2025, and the deadline for filing claims was November 6, 2025, for both past repair reimbursement and former-owner claims.
Q6. Can I still get money from the CP4 fuel pump Silverado Sierra lawsuit if I missed the November 2025 deadline?
As of early 2026, the window for filing claims for past repairs (those occurring before May 2025) has officially closed. However, the settlement remains highly relevant for current owners through the Partial Repair Reimbursement Program. If your CP4 pump fails between now and May 6, 2026, and the truck has under 200,000 miles, you can still claim a 50% reimbursement for the repair costs, provided the work is done at a GM dealership. For those who missed the deadline or own trucks purchased outside the seven states, individual Lemon Law or breach of warranty claims may still be an option.
Q7. Which states are covered in the CP4 fuel pump Silverado Sierra lawsuit settlement?
The order confirms that the certified class is all persons or entities who purchased one or more of the class vehicles from a GM-authorized dealership from March 1, 2010, to September 13, 2024, in California, Florida, Illinois, Iowa, New York, Pennsylvania, and Texas. People who bought trucks outside the seven states or after September 13, 2024, are not included in this specific settlement.
Q8. Why are only seven states covered in the CP4 fuel pump Silverado Sierra lawsuit?
In Judge Terrence G. Berg’s 53-page order, consumers’ claims were upheld under various state laws, and seven classes were certified for the states of California, Florida, Illinois, Iowa, New York, Pennsylvania, and Texas. Lawyers’ attempts to certify five other states for the class were denied. The lawsuit used specific consumer protection statutes in these states that provided the strongest legal footing for the plaintiffs’ claims.
Q9. What if I bought my Silverado or Sierra in a state not covered by the lawsuit?
If your truck was purchased used from a private party or a non-GM dealer, or if it was purchased in a state like Colorado or Ohio, you are likely excluded from this specific settlement fund. This has led to a lot of frustration in the diesel community, as the mechanical failure does not care about state lines. For those who missed the deadline or own trucks purchased outside the seven states, individual Lemon Law or breach of warranty claims may still be an option. These individual actions are often more complex but can result in full vehicle compensation.
Q10. Can I file a claim if I no longer own my Silverado or Sierra?
Reimbursement is available for past and current truck owners, but the amount of reimbursement will depend on how many GM customers file valid claims and provide supporting documentation. For reimbursement, the problems must have been caused by metal fuel pump parts that rubbed together, created metal shavings, contaminated the Duramax diesel fuel system, and caused catastrophic engine failure. Former owners who sold or traded their truck qualify for the smaller diminished-value payout.
Q11. What documents do I need to file a claim in the CP4 fuel pump Silverado Sierra lawsuit?
The required documents include: Proof of Purchase — dealer purchase documents showing you, dealer, vehicle, and date; Proof of Repair — repair invoices or payment records identifying the CP4 pump or components referenced in GM TSB 16-NA-102; Proof of Sale for former owners — sale documents with date of sale, VIN, seller, and buyer info. The stronger and more detailed your repair documentation, the smoother your claim review process will be.
Q12. Where do I file a claim for the CP4 fuel pump Silverado Sierra lawsuit?
The official settlement system has a VIN look-up tool where you enter all 17 digits of your Vehicle Identification Number to see if you are listed and receive your approximate payout. Claims are filed and managed through the official settlement website GMFuelPumpLitigation.com, administered by JND Legal Administration. No third-party claim services are required.
Q13. How do I know if my truck has the CP4 pump covered by the lawsuit?
The easiest method is the VIN checker on the official settlement website. The easiest way to confirm if your truck is included is to visit the official settlement website and enter your VIN in the eligibility checker tool, or review the Class Vehicles section of the site’s FAQ and compare your model, year, engine, and purchase details. For the LML Duramax engine, the eighth character of your VIN will be the number “8.”
Q14. Why does the CP4 fuel pump fail in American diesel trucks?
The CP4 pump is alleged to be incompatible with typical U.S. diesel fuel because the fuel has lower lubrication (“lubricity”) than what the pump was designed for. When the pump runs with insufficient lubrication, it can cause sudden loss of power or complete engine shutdown while driving, creating safety risks and expensive repairs. The pump was originally engineered for European diesel, which has significantly higher lubricity than U.S. ultra-low sulfur diesel (ULSD).
Q15. How much does it cost to repair a failed CP4 fuel pump in a Silverado or Sierra?
Repairing CP4-related damage can cost up to about $15,000 because it often requires replacing the pump, fuel lines, injectors, and related components. The lawsuit alleged the fuel pump has a fragile and unstable design which causes metal parts to rub against each other, creating metal shavings that contaminate the fuel system, and repairs cost around $12,000. Total costs vary based on how extensively the metal contamination spread through the fuel system.
Q16. Did GM admit fault in the CP4 fuel pump Silverado Sierra lawsuit?
GM denies any wrongdoing but agreed to settle the lawsuit to avoid the uncertainty and expense of continued litigation. GM has refused to accept any blame even as it agreed to pay up to $12,700 to owners affected by major injection system failures in certain Chevrolet Silverado and GMC Sierra models. This no-admission settlement structure is standard practice in large class action cases.
Q17. What is the future repair reimbursement in the CP4 fuel pump Silverado Sierra lawsuit settlement?
A future repair provision offers 50% cash back on future CP4 repair services at GM-approved dealerships, completed on or after May 6, 2025. The reimbursement will be made until May 6, 2026, or 200,000 odometer miles, whichever is reached first. For future repair reimbursement, you must submit a Reimbursement Request within 60 days of the repair.
Q18. What legal allegations were made against GM in the CP4 fuel pump Silverado Sierra lawsuit?
The lawsuits against General Motors typically include the following allegations: Breach of Warranty — GM failed to honor warranties by refusing to cover CP4 pump failures or related damage; Fraudulent Concealment — the manufacturer allegedly knew about the defect but concealed it from consumers; Negligence — GM continued using a known defective part without implementing a recall or offering a permanent solution; Unjust Enrichment — the company profited from selling vehicles with defective components while owners bore the financial burden of repairs.
Q19. When was the CP4 fuel pump Silverado Sierra lawsuit filed and when was it settled?
In 2019, owners filed the lawsuit Chapman v. General Motors LLC in a Michigan court. From 2020 to 2024, more people joined as litigation grew. In June 2024, GM agreed to pay to settle. In January 2025, the court held a final meeting to review the deal. The court’s final blessing of the settlement took place on May 6, 2025, by Judge Terrence G. Berg.
Q20. Can I still get a CP4 fuel pump repaired under the settlement in 2026?
As of early 2026, the settlement remains highly relevant for current owners through the Partial Repair Reimbursement Program. If your CP4 pump fails between now and May 6, 2026, and the truck has under 200,000 miles, you can still claim a 50% reimbursement for the repair costs, provided the work is done at a GM dealership. This is the last remaining active benefit from the settlement for current truck owners.
Q21. Does the CP4 fuel pump lawsuit also affect Ford diesel trucks?
Affected vehicles include Ford models with 6.7L Power Stroke Diesel Engines from 2011 to the present, in addition to General Motors’ Chevrolet Silverado 2500HD with 6.6L V8 Duramax Diesel LML Engines from 2011 to 2016. However, the GM and Ford cases are being litigated separately, and the settlement terms and timelines for Ford truck owners differ from the Silverado and Sierra settlement described here.
Q22. What were the signs that led to the CP4 fuel pump Silverado Sierra lawsuit being filed?
Thousands of Chevrolet Silverado and GMC Sierra owners reported catastrophic fuel system failures linked to the CP4 high-pressure fuel pump, often resulting in repair bills exceeding $10,000. Many owners reported that warranty claims were denied, with GM often attributing failures to fuel contamination rather than a defective design. As failures became more widespread, owners began filing lawsuits. The 2016 TSB issued privately to dealers — without owner notification — further fueled suspicions of concealment.
Q23. Are trucks with aftermarket fuel system modifications covered by the CP4 fuel pump Silverado Sierra lawsuit?
The deal does not cover vehicles that have been changed to use aftermarket fuel systems because this would make it difficult to assign defects. If your truck has been converted to a CP3 pump or any other aftermarket high-pressure fuel system, it is excluded from both the past repair reimbursement and the future repair coverage under the settlement terms.
Q24. What options do Silverado and Sierra owners have if they don’t qualify for the CP4 lawsuit settlement?
Although some claim deadlines have passed, owners should still check their eligibility. Some owners may still qualify for future partial repair coverage even if reimbursement deadlines have closed. For those who missed the deadline or own trucks purchased outside the seven states, individual Lemon Law or breach of warranty claims may still be an option. These individual actions are often more complex but can result in full vehicle compensation. Consulting a consumer protection attorney familiar with the CP4 litigation is strongly recommended.
