GM CP4 Fuel Pump Lawsuit, Settlement Payouts and What Duramax Owners Can Do Now

TL;DR

• The GM CP4 fuel pump lawsuit settled for $35 million in benefits to truck owners, and every claim deadline has now closed. The last one, the Reimbursement Request Form deadline, expired on July 5, 2026 (GM Fuel Pump Settlement, 2026).
• Class members who paid out of pocket for a CP4 repair were estimated to receive between $6,356 and $12,712 per repair. Former owners who never paid for a repair were estimated at $400 to $800 (GM Fuel Pump Settlement, 2026).
• Initial settlement checks were mailed on March 23, 2026, and a follow-up distribution was scheduled for August 2026 for owners who fixed a deficient claim (GM Fuel Pump Settlement, 2026).
• The class covered only buyers in California, Florida, Illinois, Iowa, New York, Pennsylvania, and Texas. Owners in the other 43 states were never class members, so they never released their claims against GM.
• GM never issued a safety recall for the CP4 pump. Chrysler recalled 222,410 Ram trucks, and Ford recalled 295,449 Super Duty trucks over the same family of pumps (NHTSA, 2021; NHTSA, 2024).

What the GM CP4 Fuel Pump Lawsuit Is About

The GM CP4 fuel pump lawsuit is a class action claiming that the Bosch CP4 high-pressure fuel injection pump in 2011 to 2016 Duramax diesel trucks is too fragile for American diesel fuel, grinds itself into metal shavings, and pushes that debris through the entire fuel system until the engine shuts down. The case is Chapman v. General Motors LLC, No. 2:19-cv-12333, filed in the U.S. District Court for the Eastern District of Michigan before Judge Terrence G. Berg.

Here is the mechanical version, minus the engineering jargon. The CP4 is a two-piston pump that squeezes diesel to roughly 30,000 psi. It has no separate oil supply. The only thing lubricating those pistons is the diesel fuel passing through it. European diesel carries more lubricity than the ultra-low-sulfur diesel sold at American pumps, so in the United States the pump runs closer to dry than it was designed to. Metal touches metal. Metal wears. The shavings then travel downstream into the injectors, the rails, and the lines. According to the settlement notice, plaintiffs allege this contamination can shut the engine down while the truck is moving (GM Fuel Pump Settlement, 2026).

The part owners hate most is the repair bill. Once metal is in the system, you cannot just swap the pump. The injectors, rails, lines and filter housing all get replaced, because a single surviving shaving takes out the new pump too. That is how a fuel pump job turns into a five-figure invoice.

GM denies the trucks are defective and denies any wrongdoing, and the court never ruled on who was right. Both sides settled instead. GM disclosed the case in its own annual report, telling investors that a class action was pending over 2011 to 2016 Duramax fuel pumps and that seven state subclasses were certified in March 2023 (General Motors, Form 10-K, 2025).

Where the GM CP4 Settlement Stands Right Now

Every single deadline in the GM CP4 settlement has passed. The court granted final approval on May 6, 2025. Claim forms were due November 6, 2025. Initial payments went out March 23, 2026. The Reimbursement Program for future repairs closed May 6, 2026, and the last form deadline expired July 5, 2026 (GM Fuel Pump Settlement, 2026).

This matters because most of the pages ranking for this topic still read like the claims window is open. It is not. If you are landing here hoping to file, the honest answer is that the filing period is over, and the useful question now is a different one, which the rest of this article answers.

Full timeline of the GM CP4 settlement

Source: GM Fuel Pump Settlement administered by JND Legal Administration, 2026.

How Much the GM CP4 Settlement Actually Paid

GM funded $35 million in direct benefits to truck owners, split into a $30 million Repair Fund and a $5 million Former Owner Fund. Payment size depended on how many valid claims came in, so the notice published ranges rather than fixed amounts. Class counsel separately asked the court for up to $15 million in fees and costs, which did not come out of the $35 million (GM Fuel Pump Settlement, 2026).

Source: GM Fuel Pump Settlement, 2026.

Two details in that table get missed constantly. First, the Repair Fund paid per repair, not per truck, so an owner who lost two pumps could claim twice. Second, the Reimbursement Program only ever covered work done at a GM-authorized dealership. An independent diesel shop invoice, even a perfect one, did not qualify.

Reality check on the numbers. Owners routinely reported CP4 repair invoices in the $8,000 to $15,000 range, and the complaint itself alleged GM charged roughly $10,000 for the repair. Even the top estimated settlement payment of $12,712 was a reimbursement of what owners already spent, not a windfall.

Which Trucks Were Covered and Which Ones Were Quietly Left Out

The settlement class was narrower than most owners assume. You were a class member only if you bought a model year 2011 to 2016 Chevrolet Silverado or GMC Sierra with a 6.6L Duramax diesel and a Bosch CP4 pump, from a GM authorized dealer, in one of seven states, between March 1, 2010 and September 13, 2024 (GM Fuel Pump Settlement, 2026).

The seven states in the GM CP4 class

The certified subclasses were California, Florida, Illinois, Iowa, New York, Pennsylvania, and Texas. That is it. Seven states out of fifty.

If you bought your Duramax in Ohio, Arizona, Colorado, Michigan or any of the other 43 states, you were never in this class. You got no notice, no claim form, and no payment. You also never gave up anything, which turns out to be the more interesting half of that sentence.

Four groups of owners the settlement never covered

1. Buyers outside the seven certified states. Geography, not the truck, decided who was in.
2. Anyone who did not buy from a GM authorized dealer. Private party purchases and independent used lots fell outside the class definition, even for an identical truck.
3. Express and Savana van owners. GM Technical Service Bulletin 16-NA-102 covers 2010 to 2016 Chevrolet Express and GMC Savana vans with the LML and LGH diesel engines alongside the Silverado and Sierra 2500 and 3500. The settlement class covers only the Silverado and Sierra pickups (GM Service Bulletin 16-NA-102, 2021).
4. Owners of 2017 and newer Duramax trucks. Those trucks do not have a CP4 at all, which is the single most common misunderstanding about this case.

Why 2017 and Newer Duramax Trucks Are Not Part of This Lawsuit

The 2017 and newer 6.6L Duramax, engine code L5P, does not use a Bosch CP4. It uses a Denso HP4 high-pressure pump, and GM made that switch specifically because of the CP4 failure pattern. If your truck is a 2017 or later Silverado or Sierra HD, the Chapman settlement never applied to you and no CP4 claim exists for your truck.

The HP4 is a different animal. It runs three pumping plungers instead of two, adds an inlet filter screen the CP4 never had, and is fed by a factory in-tank electric lift pump that keeps supply pressure steady. GM also dropped Bosch as the fuel system supplier for the L5P generation.

This is worth saying plainly because a lot of forum advice gets it wrong. A 2019 Silverado 2500 owner who reads a CP4 horror story and starts pricing a CP3 conversion is solving a problem their truck does not have. Diagnose the actual failure first.

Why GM Never Recalled the CP4 When Ram, BMW and Ford Did

There is no NHTSA safety recall covering the CP4 pump in 2011 to 2016 Duramax trucks. GM handled the problem through a technical service bulletin and, eventually, a class settlement. Other automakers using variants of the same Bosch pump took the recall route instead, which is why the regulatory record looks so lopsided.

Sources: NHTSA recall acknowledgment 21V-880, 2021, and NHTSA recall acknowledgment 24V-957, 2024.

The federal investigation that skipped GM

NHTSA does have an open file on the CP4 pump family. Its Office of Defects Investigation opened Engineering Analysis EA23-001 on March 17, 2023, upgrading an earlier Ram investigation to cover Bosch as the supplier and any manufacturer using the same pump. The resume for that analysis lists an estimated population of 490,000 vehicles, 794 complaints, and 7,704 warranty claims and field reports, with zero crashes, fires, injuries, or fatalities recorded (NHTSA ODI Resume EA23-001, 2023).

Here is the part nobody covers. When NHTSA wrote to Bosch in March 2024 listing the subject vehicles, the list ran through BMW 328d, 535d, 740Ld, X3 and X5 models and Ram 1500, 2500, 3500, 4500 and 5500 trucks plus the Jeep Grand Cherokee, Gladiator and Wrangler. The 2011 to 2016 Duramax is not on it (NHTSA Information Request EA23-001, 2024). The agency counted nine CP4-related recalls from Chrysler and BMW alone. GM filed none.

Ford eventually joined that recall column, and the paper trail there is telling. Ford recall 24S78, filed with NHTSA as 24V-957, describes aged biodiesel deposits forming on the pump drivetrain roller and in the tappet body cooling passages, causing increased wear and metal debris in the fuel system (NHTSA Part 573 Report 24V-957, 2024). Same debris, same loss of motive power, different label on the cause.

If you own a Ford Super Duty rather than a Duramax, the practical differences matter a lot. Our breakdown of the Ford CP4 recall and what the software only remedy does and does not fix covers that side.

How to Tell If Your CP4 Is Failing Before It Takes the Whole Fuel System

The earliest reliable warning is magnetic metal debris on Fuel Pressure Regulator 1. GM built its whole diagnostic procedure around that check. Bulletin 16-NA-102 tells technicians to pull the injection pump, remove Fuel Pressure Regulator 1, and inspect the screen for debris that can be picked up with a magnet before deciding how far the contamination has spread (GM Service Bulletin 16-NA-102, 2021).

Symptoms GM lists in its own bulletin

• Hard starting, where the engine cranks noticeably longer than normal before catching.
• No start at all, often after the truck ran fine the day before.
• Diagnostic trouble code P0087, fuel rail low pressure.
• Diagnostic trouble code P0088, fuel rail high pressure.
• Diagnostic trouble code P0191, fuel rail pressure sensor performance.
• Diagnostic trouble code P128E, fuel rail pressure performance.

Source: GM Service Bulletin 16-NA-102, 2021.

Owners describe one more tell that no bulletin mentions. When you drop the fuel filter, hold it up to the light and look at the pleats. If you see what looks like fine glitter, that glitter is your pump. By the time it is visible, the injectors have usually already been drinking it.

If your truck is doing this right now, document before you repair. Photograph the filter, keep the old parts, and ask the dealer in writing to note the debris finding on the repair order. A repair order that says “replaced fuel pump” is worth far less to you later than one that says “magnetic debris found on Fuel Pressure Regulator 1.” That single sentence is the difference between a provable claim and a story.

What Owners Outside the Seven States Can Still Do

Owners outside California, Florida, Illinois, Iowa, New York, Pennsylvania and Texas were never class members, so they never released any claims against GM. Legally, their claims are still their own. Practically, the obstacle is timing, because these are 2011 to 2016 trucks and most state deadlines for warranty and consumer protection claims are measured in a handful of years.

That tension is the honest answer, and it is more useful than the version most sites give you. Three things decide whether anything is left.

1. When the clock started: Some states start the limitations period at purchase. Others start it when the buyer discovered, or reasonably should have discovered, the problem. A pump that failed in 2023 on a 2015 truck lands very differently in those two systems.
2. Whether the pending class action paused the clock: Federal law has a doctrine that can toll limitations periods for absent class members while a class action is pending. How it applies to someone in a state whose subclass was never certified is a fact-specific question, not a yes or no.
3. Whether concealment is alleged: Where a manufacturer is alleged to have hidden a defect, some states delay the start of the clock. The Chapman plaintiffs alleged exactly that kind of concealment, and GM denied it.

None of that is something to guess at from a forum thread. It is a fifteen-minute conversation with a lawyer who can look at your purchase date, your repair dates, and your state. Our state by state lemon law and vehicle defect pages are a reasonable starting point for the ground rules where you live.

What the settlement release did not cover

Even for class members, the release had limits worth knowing. By staying in the class, members released economic loss claims tied to the CP4 pump. The settlement expressly did not release claims for death, personal injury, damage to property other than the truck itself, or subrogation (GM Fuel Pump Settlement FAQ 16, 2026).

That carve-out is not theoretical. A pump failure that shuts an engine down at highway speed while towing is a crash scenario, and the settlement left injury claims from that kind of event untouched.

Class Action Versus Lemon Law, Which Route Pays a Truck Owner More

An individual lemon law or warranty claim almost always pays more per owner than a class action, because a class divides a fixed fund across thousands of people while an individual claim is measured against one vehicle. The GM CP4 settlement is a clean illustration. A $30 million fund spread across a nationwide problem produced an estimated $6,356 to $12,712 per repair, while a successful buyback on a single truck is calculated from what that owner actually paid.

This is also why opting out of a class is sometimes the better move for an owner with a large, well-documented loss, and why the December 12, 2024 opt-out deadline mattered more than most class members realized at the time. If you want the mechanics of the tradeoff, we cover it in how to join a GM class action lawsuit and when you should not, and in how a GM lemon law buyback is calculated.

You can run rough numbers yourself with our lemon law buyback calculator, and if the cost question is holding you back, lemon law attorneys are almost always paid by the manufacturer, not by you.

What to Do If You Filed a CP4 Claim and Still Have No Money

If you filed a valid claim and have not been paid, the most likely reason is a Notice of Deficient Claim, which the settlement administrator sends when documentation is incomplete. Initial payments went out March 23, 2026, to claims that were already validated, and an additional distribution was scheduled for August 2026 for class members who supplied the missing documents (GM Fuel Pump Settlement, 2026).

1. Check your mail and email, including spam, for anything from JND Legal Administration or the GM Fuel Pump Settlement. Deficiency notices are easy to mistake for junk.
2. Contact the settlement administrator directly at 1-866-848-0815 or . Dealerships cannot look up your claim, cannot pay you, and cannot answer settlement questions.
3. Pull together proof of purchase from a GM authorized dealer in a class state, proof of the CP4 repair naming the covered parts, or proof of sale if you claimed as a former owner.
4. If a check was issued but never arrived, ask the administrator about reissue rather than assuming the claim failed.

Everything above runs through the official GM Fuel Pump Settlement website, which is administered by JND Legal Administration under court supervision. Any site charging you a fee to file is not it.

What Duramax Owners Are Actually Asking, and the Short Answers

People no longer type three-word keywords into a search box. They describe the whole situation and expect an answer. These are the questions this topic generates most often, answered in one paragraph each.

“My 2014 Silverado 2500 shut off on the highway and the dealer says metal went through the whole fuel system, is there a lawsuit”

Yes, and it already settled. Chapman v. General Motors covered exactly that failure mode on 2011 to 2016 Duramax trucks, and every claim deadline closed by July 5, 2026. Whether anything is left for you depends on which state you bought in and when the failure happened. Save the repair order that documents the metal debris either way.

“I paid $11,000 for a Duramax fuel pump in 2022, did I miss the GM settlement”

If you bought the truck new or used from a GM authorized dealer in one of the seven class states and did not file by November 6, 2025, then yes, that window closed. If you bought outside those states you were never eligible to file in the first place, which is a different problem with different options.

“I live in Ohio and own a 2015 Sierra 2500, why was I not in the GM CP4 settlement”

Because the court certified subclasses under the consumer protection and warranty laws of seven specific states, and Ohio was not one of them. Your truck was not less defective. Your state law simply was not part of the certified class. You also never released your claims, which is the one advantage of being left out.

“Does the CP4 settlement cover my 2019 Duramax”

No. Model year 2017 and newer 6.6L Duramax trucks use the Denso HP4 pump, not the Bosch CP4, and the class stopped at 2016. If your 2019 truck has a fuel system failure, that is a warranty question rather than a CP4 class action question.

“I got a deficient claim letter from the GM fuel pump settlement, what now”

Send the administrator whatever document the letter says is missing, usually proof of purchase from a GM authorized dealer or a repair order that names the specific parts replaced. Cured claims were being paid in a rolling additional distribution. Call 1-866-848-0815 before assuming the claim is dead.

“Is there a recall on the Duramax CP4 fuel pump”

No. GM never issued one for the 2011 to 2016 Duramax. Chrysler recalled 222,410 Ram trucks under NHTSA campaign 21V-880, and Ford recalled 295,449 Super Duty trucks under 24V-957 over the same pump family, which is why owners assume a GM recall must exist somewhere. It does not.

“My fuel filter looks like it has glitter in it”

That glitter is metal from the pump, and it is the classic CP4 signature. Stop driving the truck, photograph the filter, and get it to a shop before the debris finishes off the injectors. Ask for the finding to be written on the repair order in those words.

If Your Newer GM Diesel Is Failing, You Have a Live Claim Right Now

Owners of newer GM trucks with repeated unfixed defects are in a much stronger position than 2011 to 2016 CP4 owners, because their vehicles are still inside the warranty period where state lemon laws apply. A class action pays a share of a fund years later. A lemon law claim on a current truck can produce a repurchase or replacement while you still own it.

The threshold in most states is a repeated failure the dealer cannot fix, or a vehicle out of service for an extended stretch of days. Our guides on how many repair attempts it takes before a vehicle qualifies, what happens when the dealership cannot fix your car, and how long a dealership can hold your vehicle for repair walk through the specifics.

GM has more than one open defect story running at the moment. If your truck or SUV is affected by the 6.2L L87 engine litigation or the valve lifter failures, those are separate matters with their own timelines. Owners researching a specific model can also start from our Chevrolet and GMC pages.

If your vehicle is used and out of the original warranty, the federal lemon law for used cars can still apply through the Magnuson-Moss Warranty Act, and how a lemon law claim actually works start to finish explains the sequence.

Frequently Asked Questions About the GM CP4 Fuel Pump Lawsuit

What is the GM CP4 fuel pump lawsuit?

It is a class action called Chapman v. General Motors LLC, No. 2:19-cv-12333, in the U.S. District Court for the Eastern District of Michigan. Plaintiffs alleged that the Bosch CP4 high-pressure fuel pump in 2011 to 2016 Duramax trucks is unreasonably fragile, generates metal shavings that contaminate the fuel system, and can shut the engine down. GM denied the allegations, and the court never ruled on the merits.

Is the GM CP4 settlement still open?

No. The court granted final approval on May 6, 2025. The deadline to file a claim for past repairs or as a former owner was November 6, 2025. The Reimbursement Program closed on May 6, 2026, or at 200,000 miles, and the final Reimbursement Request Form deadline was July 5, 2026 (GM Fuel Pump Settlement, 2026).

How much did the GM CP4 settlement pay per person?

The notice estimated about $12,712 per repair if 25 percent of eligible owners claimed, or about $6,356 if 50 percent claimed. Former owners who never paid for a repair were estimated at $400 to $800 depending on claim volume. Actual amounts depended on final claim counts (GM Fuel Pump Settlement, 2026).

Which trucks were included in the GM CP4 class action?

Model year 2011 to 2016 Chevrolet Silverado and GMC Sierra trucks with the 6.6L Duramax diesel and a Bosch CP4 pump, bought from a GM authorized dealer in California, Florida, Illinois, Iowa, New York, Pennsylvania or Texas between March 1, 2010 and September 13, 2024.

Is there a GM CP4 fuel pump recall?

No. There is no NHTSA safety recall campaign covering the CP4 pump in 2011 to 2016 Duramax trucks. GM addressed the failure through Technical Service Bulletin 16-NA-102, which is a repair procedure, not a free repair program.

Why did Ram and Ford recall their CP4 pumps but GM did not?

Chrysler filed NHTSA recall 21V-880 in November 2021 covering 222,410 Ram trucks and replaced the pump outright. Ford filed 24V-957 in December 2024 covering 295,449 Super Duty trucks with a software update. GM chose to litigate and then settle instead. NHTSA counted nine CP4-related recalls from Chrysler and BMW when it opened Engineering Analysis EA23-001 in 2023 (NHTSA, 2023).

Does the CP4 lawsuit cover 2017 and newer Duramax trucks?

No. The 2017 and newer L5P Duramax uses a Denso HP4 pump rather than a Bosch CP4. GM changed suppliers for that engine generation, and the class definition stops at model year 2016.

I bought my Duramax outside the seven states; do I have any claim left?

You were never a class member, so you never released your claims against GM. Whether a claim is still viable depends on your state limitations period, when the failure was discovered, and whether tolling applies. That is an individual legal question and worth a free case review rather than a guess.

What are the warning signs of CP4 fuel pump failure?

Hard starting, a no-start condition, and diagnostic trouble codes P0087, P0088, P0191, or P128E, per GM Service Bulletin 16-NA-102. The physical tell is magnetic metal debris on Fuel Pressure Regulator 1 or fine metallic glitter visible in the fuel filter.

How much does a CP4 fuel pump failure cost to repair?

Repairs commonly ran into five figures because contamination requires replacing the injectors, rails, lines, and filter housing rather than the pump alone. The underlying complaint alleged GM charged roughly $10,000 for the repair, and the settlement estimated payments of up to $12,712 per repair to reimburse owners.

Can I still sue GM individually over a CP4 failure?

If you were a class member and did not opt out by December 12, 2024, you released your economic loss claims against GM over the CP4 pump. Claims for death, personal injury, property damage other than the truck itself, and subrogation were not released. Owners who were never class members did not release anything.

Who do I contact about a GM CP4 settlement payment?

The settlement administrator, JND Legal Administration, at 1-866-848-0815 or . Do not contact the court or GM about settlement payments, and be aware that GM dealerships cannot look up or process settlement claims.

Where This Leaves Duramax Owners

The CP4 chapter is closed for most 2011 to 2016 owners, and pretending otherwise does nobody any favors. What is still open is narrower and more specific. Class members with a cured deficient claim were being paid into August 2026. Owners in the 43 states outside the class never released their claims, though timing is a real hurdle. Injury and property damage claims survived the release entirely. And owners of newer GM diesels sitting through repeat repairs have a far stronger and far faster route through their state lemon law than any class action was ever going to give them.

If you are holding a repair invoice and are not sure which of those categories you are in, that is exactly the question worth putting in front of a lawyer. Tell us what happened and we will tell you straight whether there is anything there. Case reviews are free, and in warranty cases the manufacturer typically pays attorney fees, not you.

Sources

• GM Fuel Pump Settlement, Chapman v. General Motors LLC, official settlement website administered by JND Legal Administration.
• GM Fuel Pump Settlement, Frequently Asked Questions, class definition, payment estimates and release scope.
• NHTSA Office of Defects Investigation, Resume for Engineering Analysis EA23-001, high pressure fuel pump failure.
• NHTSA Office of Defects Investigation, Information Request to Robert Bosch LLC, EA23-001, subject vehicle list.
• NHTSA, Recall Acknowledgment 21V-880, Chrysler (FCA US), high pressure fuel pump may fail.
• NHTSA, Recall Acknowledgment 24V-957, Ford Motor Company, high pressure fuel pump.
• NHTSA, Part 573 Safety Recall Report 24V-957, cause and safety risk description.
• GM Service Bulletin 16-NA-102, Duramax diesel hard start, no start, DTCs P0087, P0088, P0191, P128E or injection pump replacement.
• General Motors Company, Form 10-K for fiscal year 2024, litigation disclosure on Duramax fuel pump class action.

Disclaimer: This article is general information about vehicle defect litigation and consumer warranty law. It is not legal advice and does not create an attorney client relationship. Deadlines, case status and remedies change. Verify current information with the official settlement administrator or a licensed attorney in your state before acting.