Introduction
If you’re a former owner (or current owner) of the 2011-2016 Chevrolet Silverado or GMC Sierra 6.6L Duramax diesel, chances are you’re already familiar with the cp4 fuel pump silverado sierra lawsuit. After years of lawsuit battles, a federal court-based national class action settled in 2025 on a settlement that provides actual cash—and limited future repair protection—to qualified owners. This brochure describes the pump in scandal, how the case progressed, what trucks and states are involved, what is part of the settlement, what are the important deadlines, and information about how to protect your engine and your purse.
The short version
The lawsuit: Chapman, et al. v. General Motors LLC, No. 2:19-cv-12333 (E.D. Mich.), was aimed at the Bosch CP4 high-pressure fuel pump on the LML/LGH-model Duramax. The CP4 was blamed by plaintiffs for not being strong enough for U.S. diesel fuel and for eventually failing spectacularly, pushing metal into the fuel system and even stalling the engine. GM made no admission of wrongdoing.
Who is eligible: Buyers of 2011–2016 Silverado/Sierra 6.6L Duramax pickup trucks purchased from GM dealerships in CA, FL, IL, IA, NY, PA, or TX from Mar. 1, 2010 through Sept. 13, 2024. (Where you bought it—those seven states—matters.) Use the settlement site’s VIN checker.
What it pays:
- Pre-repair cost: Approximately $6,356–$12,712 per CP4 repair for typical claims.
- Prior owners (no repair paid): Approximately $400–$800 pro rata.
- Future repairs: 50% credit on eligible CP4 repairs completed at GM dealerships May 6, 2025, to May 6, 2026 (or to 200,000 miles), within 60 days of the repair.
- Deadlines: November 6, 2025, is the deadline for cash claim forms (previous repairs or previous owners). Future repair payments are within 60 days of the repair and the program terminates May 6, 2026 (or 200k miles first).
- Total cost: The settlement estimates its total cost at around $50 million (in fees), $30 million to repair and $5 million to earlier owners—costs sworn to by class counsel.
GM Authority
Hagens Berman
What is a CP4 pump and why did it so create a firestorm?
Modern common-rail diesels operate very high pressure. Bosch CP4 is a smaller, high-pressure, high-efficiency pump that was brought out to satisfy more stringent emissions without adding additional parasitic loss. The general complaint on most companies (not only GM) is that the CP4 will “run dry,” gall internally, and wear metal, clog injectors, rails, and lines. Since the debris is cycled under pressure, a failure will result in replacing most of the fuel system—a multi-thousand-dollar endeavor. Though proper failure rate is questionable, repair is heartbreaking when it occurs. Diesel Power Products
In GM class action, the CP4 was claimed by plaintiffs to be “unreasonably brittle” in U.S. fuel conditions and GM did not disclose the risk; GM replied so not so and asserted the trucks were not defective. The court never ruled who was correct—parties preferred ducking trial risk and cost.
Who are qualified trucks and owners?
You qualify based on what you purchased, where, and when:
Model years: 2011–2016
Vehicles: Chevrolet Silverado or GMC Sierra 6.6L Duramax diesel pickup trucks with a Bosch CP4 fuel pump high pressure
Where bought: You have to have bought from an authorized GM dealer in one of seven states: California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas
When bought: March 1, 2010 – September 13, 2024
If that’s the way you originally purchased your truck, then you are a member of the settlement class whether or not you still own the truck. The website even has a VIN check that you can use to confirm.
Note: The geographical limit of the settlement—shielding trucks purchased from dealers in only seven states—has been the most irritating source of frustration for truck owners in any state other than those. But for purposes of the settlement, they are the rules the court upheld.
What the settlement pays (and how to qualify)
The settlement provides relief into three categories.
1) Pre-May 6, 2025 out-of-pocket CP4 repairs
If you are reimbursed in advance for a CP4 repair prior to May 6, 2025, you will be paid in cash from the $30 million Repair Fund. The net dollar amount computed on the number of eligible payees that get reimbursed for repair claims:
If 25% of eligible claimants are reimbursed: ~$12,712 per repair
If 50% reimburse eligible claims: ~$6,356 per repair
Evidence needed: file in your name with the VIN and repairs done or replaced under listed items (i.e., repair slips, invoices). Without repair files, you may verify payment with a signed affidavit (form with claim).
Due date: November 6, 2025.
2) Former owners who never paid for repairs
Sold the truck prior to May 6, 2025, and failed to purchase a CP4 repair? You may be entitled to a pro rata payment out of the $5 million Former Owner Fund. Volume of claim-based estimates are ~$400–$800 per class member. Deadline: November 6, 2025.
3) Future repair reimbursement (12-month window)
For work completed on or after May 6, 2025, the settlement provides 50% cash-back for eligible CP4 repairs at authorized GM dealerships. You must submit for reimbursement in 60 days from repair. The program expires on May 6, 2026 (or at vehicle mileage of 200,000 miles, whichever occurs first). Payments are made for valid requests within 60 days or fewer from receipt.
Items listed are addressed in GM TSB 16-NA-102 (parts and diagnostics associated with fuel-system contamination). The procedure and parts list are explained in the documents and FAQs on the settlement website.
Timeline & filing details
Date final approval was granted: May 6, 2025
Deadline for claim (previous repairs & previous owners): November 6, 2025
Window of future repair coverage: May 6, 2025 → May 6, 2026 (or 200,000 miles)
Future claim for reimbursement of repair: to be made within 60 days of date of repair
Online filing option, VIN search to validate eligibility, all FAQ to be hosted on settlement site.
How we got here: Chronology of events summary
2019: Chapman lawsuit filed in Eastern District of Michigan (Detroit).
2023–2024: Case remains pending; settlement terms and notice ratified by court. The public is not sure of its forecast since news continues to evolve, but the model—repair fund, old-owner fund, and limited future reimbursement—remains the same.
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January 2025: Initial date set for final approval hearing, which is subsequently delayed.
April 25, 2025: Final approval hearing.
May 6, 2025: Last approval issued; future-repair reimbursement period of 12 months begins on this date.
Newspaper accounts set total value of settlement at approximately $50 million with class counsel to contribute $30 million for repair and $5 million for former owners. (Court approved attorney fees and costs separately and do not deduct from two funds.)
Hagens Berman
GM Authority
Practical guidance for cp4 fuel pump silverado sierra lawsuit equipped Duramax owners
1) If your truck qualifies, apply now
Buy records of a legitimate one of seven class period vehicles from a GM-dealer.
Repair record (if yes): orders or receipts with VIN and materials plus.
Prior owners with no repair charges: proof of you as owner and seller of truck prior to May 6, 2025.
Clean paper facilitates claim process and minimizes risk of delay or denial.
2) Breakdown during the 12-month time frame (through and including May 6, 2026)
Proceed through an approved GM dealer—that has to be 50% reimbursement qualified.
Keep all documentation: diagnosis notes, CP4 parts list by TSB 16-NA-102, work line, and final invoice.
Ship within 60 days of repair. Entries that are made in a timely fashion can help keep it from slipping through the cracks.
3) Preventative steps that are beneficial to any CP4 system
Nobody is advocating a particular “technique” of “avoiding” mechanical failure, but some things are always advised by diesel experts:
Guzzle good high-rate-volume diesel; do not run low on fuel (the CP4 is fuel-lubricated).
Change the fuel filter at or at recommended maintenance; use water-separating filters where they are available.
Monitor for tell-tale symptoms early: hard start, rough idle, metal in filter, DTCs on rail pressure issues—get it checked out right away.
They are overall best practices of the diesel community; they will not ensure a CP4 will not fail, but lower risk exposures that are generally created by contamination and low lubricity.
Diesel Power Products
4) Thinking about a CP3 conversion?
Some owners of other models have decided to go back to the older CP3-type pump before the CP4 based on perceived durability. Caveat emptor
Legality/warranty: Remanufactured emissions parts can create warranty and legality issues.
Settlement coverage: The settlement pay is only for covered CP4 repairs performed at GM dealerships; conversions from other aftermarket sources won’t be covered under this settlement.
Research a highly respected diesel shop and investigate relevant laws and warranty requirements before performing the modifications. (Not an attorney consultation but merely information.)
Frequently asked questions
Does where I currently live—or where I bought—matter?
It does matter where you bought the truck: a GM-dealer in CA, FL, IL, IA, NY, PA, or TX for class. Your current home is not what makes it so.
If I bought from a private seller or out-of-state dealer?
These sales, private-party or in states other than the seven listed, are not included in this settlement. (You might consider talking with an attorney regarding individual alternatives, but class recoveries will not be yours.) How much will I actually get for a prior repair?
It’s a percentage. There are two figures provided in the settlement: on the order of $12,712 if 25% claim and on the order of $6,356 if 50% claim. Your figure is the same as the rest of yours and is not bill-by-bill negotiated reimbursement.
Am I covered if my pump breaks after May 6, 2026?
No. Future protection is a 12-month warranty (May 6, 2026 date of expiration) or until the truck is at 200,000 miles, whichever comes first. Payment on a settlement basis after that doesn’t occur.
Can I have repair under future protection done in a non-GM repair facility?
No. Payment is to be made at a GM-dealer.
If I did nothing?
You’re still covered under the release of the settlement if you’re a class member. You have to submit a claim to receive cash (unless you receive payment directly from the administrator).
How this settlement stacks up in the CP4 world
The CP4 problem has generated litigation across the board, not only at GM.
Ford Power Stroke owners and others have filed individual claims on comparable metal-debris failure and expensive system replacement. The GM settlement is one of the bigger structured settlements, with a cash retro fund in addition to a short, partial future-coverage window to catch failures near the point of approval. Independent diesel sources have made long histories of cp4 fuel pump silverado sierra lawsuit for many years now, and they are nearly the same as the complaints here—despite defect denial by GM, and notwithstanding the court’s failure to make any findings of liability. Diesel Power Products Step-by-step: Filing a valid claim
Check for eligibility. Read the VIN tool and read the who’s included again.
Gather evidence.
Buy records of dealer, state, and dates.
VIN repair reports and parts repaired (or proof of payment + statement if reports are not given).
- Select claim type.
- Previous Repair Claim (in case paid by you) or
- Former Owner Claim (in case sold prior to May 6, 2025 and not paid for repair).
Submit on time. November 6, 2025 for cash claims; 60 days for any future pay for repair within the 12-month period.
Monitor correspondence. Document what is sent and monitor follow-up action by Settlement Administrator (JND Legal Administration).
What this will do for the value and credibility of affected trucks
Resale value: A paid final settlement can create higher expectations among sellers and buyers for written documentation of previous repairs and exclusions on future coverage (if within the window). Written settlement involvement can reduce stigma among some buyers, but opinions vary.
Ownership calculus: If you’re still running a CP4-equipped LML/LGH truck, the best practical strategy is meticulous maintenance, clean fuel practices, and prompt diagnosis of any fueling irregularities. During the 12-month window, repairs at a GM dealer are partially reimbursable—after that, it’s back to normal ownership risk.
Final take
The cp4 fuel pump silverado sierra lawsuit. The 2025 settlement does not take away anything of the past or promise anything new for the future without bounds, but provides significant cash to the majority who paid out of pocket and some safety-net insurance for flaws next year after approval is settled. The catch—and it’s a big one—is that one must be where the truck was purchased (one of seven states) and adhere to strict time limits.