Duramax Owners, CP4 Pump Destroyed Your Engine? Claim Deadline PASSED—But You Still Have Options Until May 2026
The November 6, 2025 deadline to file claims for the $50 million GM CP4 fuel pump settlement has passed. However, if you own a 2011-2016 Silverado or Sierra with the 6.6L Duramax, you can still receive 50% reimbursement for CP4 repairs performed at GM dealerships until May 6, 2026, or 200,000 miles—whichever comes first. The lawsuit alleged Bosch CP4 fuel pumps were incompatible with American diesel fuel, causing catastrophic failures that scattered metal shavings throughout fuel systems and resulted in $8,000-$15,000 repair bills.
What Happened: The GM CP4 Settlement You Missed
U.S. District Judge Terrence G. Berg granted final approval on May 6, 2025, authorizing a $50 million settlement fund. The November 6, 2025 deadline for past repair claims expired two weeks ago.
Thousands of truck owners submitted claims before the deadline. Those who paid for CP4 repairs are receiving between $6,356 and $12,712. Former owners without repairs qualified for $400-$800 payments.
What You Can Still Do If You Missed the Deadline
Future Repair Warranty (Active Until May 6, 2026)
Current owners who experience CP4 pump failures can still receive 50% reimbursement for:
- CP4 fuel pump replacement parts and labor
- Diagnostic testing at GM-authorized dealerships
- Mechanical damage to related components listed in Technical Service Bulletin 16-NA-102
- Fuel injector replacements caused by pump contamination
The partial warranty runs until May 6, 2026, OR until your truck reaches 200,000 miles from the original sale date—whichever comes first.
How to Get 50% Back on Future CP4 Repairs
You must follow these steps exactly:
- Use Only GM-Authorized Dealerships: Independent shops don’t qualify—repairs must be performed at certified GM dealerships.
- Document the Failure: Have the dealership confirm the CP4 pump failed due to metal shavings, contamination, or the defects covered under the settlement.
- Submit Reimbursement Request Within 60 Days: After completing repairs, submit your claim form with repair invoices to the settlement administrator within 60 days.
- Include Required Documentation: You’ll need the repair order showing your name, VIN, date of service, covered components replaced, and total cost paid.
Even with 50% reimbursement, owners facing a $14,500 repair bill will still pay over $7,000 out of pocket.
Which Trucks Are Covered by the Settlement
Eligible Vehicles:
- 2011-2016 Chevrolet Silverado 2500HD/3500HD diesel trucks
- 2011-2016 GMC Sierra 2500HD/3500HD diesel trucks
- Equipped with 6.6L Duramax LML V8 engines
- Equipped with Bosch CP4 high-pressure diesel fuel pumps
Purchase Requirements: You must have purchased the truck from a GM-authorized dealership in California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas between March 1, 2010, and September 13, 2024.
If you own one of these trucks in another state, you’re not covered by this settlement—despite having the exact same defective pump.
Why the CP4 Pump Destroys Duramax Engines
The lawsuit alleged the Bosch CP4 pump was designed for European diesel fuel, which contains more lubrication than American ultra-low-sulfur diesel. U.S. diesel reportedly runs the pump nearly dry, causing metal-on-metal contact that generates debris.
When the CP4 pump fails, it secretly deposits metal shavings and particles throughout the entire fuel system—contaminating fuel lines, fuel rails, injectors, and eventually the engine itself. Trucks shut down suddenly without warning, often while driving, leaving owners stranded and facing catastrophic repair bills.
According to the lawsuit, GM knew about the CP4 defect even before production began but allegedly concealed the problem from consumers and continued selling trucks with pumps they knew would fail.
What the November Settlement Paid (Deadline Passed)
Tier 1 – Past Repair Reimbursement (Deadline: November 6, 2025) Owners who documented CP4 repairs with invoices received $6,356 to $12,712. This deadline has passed—no new claims accepted.
Tier 2 – Former Owner Compensation (Deadline: November 6, 2025) Former owners who sold trucks without paying for repairs received $400-$800. This deadline has passed.
Tier 3 – Future Repair Warranty (Active Until May 6, 2026) Current owners can still receive 50% reimbursement on qualifying CP4 repairs at GM dealerships until May 2026 or 200,000 miles.
Real Truck Owner Experiences With CP4 Failures
One Silverado owner reported: “I had a 2016 Silverado with the 6.6 duramax engine I had 94,000 on it when my fuel pump exploded and it cost me $700.00 to get it towed back to my dealership and it cost me $14,500.00 to get it fixed and two weeks without work.”
Another owner stated: “I have a 2016 gmc 2500hd Denali that the cp4 pump exploded into my fuel system gm refused to warranty. Cost me over 10k to fix along with tow and lost of use for 6 weeks.”
A third owner noted: “I’m on my 3rd cp4 fuel injection pump and system, this has really been a very costly deal for everyone who purchased these trucks.”
Warning Signs Your CP4 Pump Is Failing
Watch for these symptoms:
- Hard starting or extended cranking before the engine fires
- Loss of power or acceleration, especially under load
- Rough idling or unusual engine noises
- Check engine light with fuel system codes
- Engine stalling while driving without warning
- Metal shavings visible in fuel filter during service
If you experience any of these symptoms, take your truck to a GM dealership immediately—before the pump completely fails and contaminates your entire fuel system.
The CP3 Conversion Alternative
Many Duramax owners are abandoning the defective CP4 entirely and converting to the older, more reliable CP3 fuel pump design used in pre-2011 trucks.
The CP3 conversion costs $2,000-$4,000 but eliminates the catastrophic failure risk. Several aftermarket companies offer CP3 conversion kits specifically for 2011-2016 Duramax engines.
Ram/Cummins recognized the CP4 problem and issued a recall for 2019-2022 models, retrofitting trucks back to CP3 pumps. GM chose the settlement route instead.
What GM Got Away With in This Settlement
GM paid $50 million to settle but admitted no wrongdoing. The settlement releases GM from all future CP4-related claims.
The attorneys representing plaintiffs received $15 million—30% of the total settlement. The 11 named plaintiffs received $5,000 each.
GM still installs identical replacement CP4 pumps during repairs, meaning “fixed” trucks remain vulnerable to the same failure within months or years.
Settlement Funds Distribution Breakdown
Total Settlement: $50 million
Repair Fund: $30 million for owners who paid for CP4 repairs (November deadline passed)
Former Owner Fund: $5 million for those who sold trucks without repairs (November deadline passed)
Attorney Fees: $15 million to law firms representing plaintiffs
Future Warranty Coverage: 50% reimbursement through May 6, 2026 (still active)
Why Only Seven States Qualified
The class certification granted by Judge Berg applied only to vehicle owners in California, Florida, Illinois, Iowa, New York, Pennsylvania, and Texas who purchased during the class period.
Owners in the remaining 43 states with identical trucks and identical failures received nothing—despite paying the same repair costs and experiencing the same defective pumps.
What Truck Owners Are Saying About the Settlement
Forum discussions reveal widespread frustration:
“This does not make a lot of sense. If the CP4 is replaced with another CP4 and still run in a state where the fuel is incompatible, isn’t the new CP4 going to go out in about the same amount of time?”
“Paying 11 people a measly $5k and handing out some extended warranties in only 7 states (that the owners still have to pay half the bill on!), all without having to admit culpability. Saying they ‘lost’ the lawsuit is a huge stretch.”
“Why is Arizona not on the list? My 2012 Duramax lml cp4 recently gave out and I paid close to 12 grand for parts and labor to install (upgrade) to a cp3 along with injectors, & cleaning the fuel tank.”
Contact Settlement Administrator for Questions
GM Fuel Pump Settlement
- Website: www.GMFuelPumpLitigation.com
- Email: [email protected]
- Phone: 1-866-848-0815
- Mail: c/o JND Legal Administration, PO Box 91445, Seattle, WA 98111
What to Do Right Now If You Own an Affected Truck
1. Check Your VIN Eligibility Visit www.GMFuelPumpLitigation.com and use the VIN lookup tool to confirm if your truck is covered.
2. Monitor for Failure Symptoms Watch for hard starting, power loss, rough idling, or check engine lights. Address symptoms immediately before catastrophic failure.
3. Use Diesel Fuel Additives Many owners report using lubricity-enhancing fuel additives like Optilube XPD or Hot Shot’s Everyday Diesel Treatment to reduce CP4 wear.
4. Consider CP3 Conversion If your pump hasn’t failed yet, the $2,000-$4,000 CP3 conversion may be cheaper than waiting for a $15,000 catastrophic failure.
5. Document Everything If repairs become necessary, save all invoices, repair orders, and diagnostic reports. You have until May 2026 for 50% reimbursement claims.
Legal Background: Chapman v. General Motors
The consolidated lawsuit was filed in U.S. District Court for the Eastern District of Michigan under case number 2:19-cv-12333-TGB-DRG.
Several individual lawsuits were consolidated into the master case:
- Berry v. Robert Bosch
- Click v. GM
- Chapman v. General Motors (Master lawsuit)
- Hockensmith v. Robert Bosch
- Martinez v. Robert Bosch
- Moonan v. General Motors
- Ginebra v. General Motors
Plaintiffs were represented by Hagens Berman Sobol Shapiro LLP, Hilliard Martinez Gonzalez LLP, and The Miller Law Firm P.C.
Frequently Asked Questions About the GM CP4 Settlement
Q: Can I still file a claim if I missed the November 6 deadline?
No. The deadline for past repair reimbursement and former owner compensation has passed. You cannot submit new claims for repairs performed before November 6, 2025.
Q: What can I still get from the settlement?
If you currently own an affected truck and need CP4 repairs, you can receive 50% reimbursement for repairs performed at GM-authorized dealerships until May 6, 2026, or until your truck reaches 200,000 miles.
Q: My CP4 pump failed last month but I got it fixed at an independent shop. Can I get reimbursed?
No. The future repair warranty only covers work performed at GM-authorized dealerships. Independent shop repairs don’t qualify.
Q: Does the settlement fix the problem?
No. GM still installs identical CP4 pumps during repairs. The fundamental incompatibility with American diesel fuel remains. Many owners are converting to CP3 pumps instead.
Q: I live in Arizona and my CP4 pump failed. Why am I not covered?
The settlement only covers purchases made in California, Florida, Illinois, Iowa, New York, Pennsylvania, and Texas. Owners in other states with identical trucks and identical failures are excluded from the settlement.
Q: How long do I have to submit a reimbursement request after future repairs?
You must submit your claim within 60 days of completing the repair at a GM dealership.
Q: What evidence do I need for future repair reimbursement?
You need repair invoices showing your name, VIN, date of service, parts replaced, labor performed, and total cost. The dealership must document that the failure was caused by the CP4 defect.
Q: Will GM replace my CP4 with a CP3 pump?
No. GM installs another CP4 pump during warranty repairs. If you want a CP3 conversion, you must arrange and pay for it yourself through aftermarket suppliers.
The Bigger Picture: Why This Settlement Matters
This settlement sets a precedent for CP4 fuel pump defects across the diesel truck industry. Ford uses the same Bosch CP4 pump in 2011-present 6.7L Power Stroke engines, and similar lawsuits are ongoing.
The limited geographic scope—only seven states—and GM’s refusal to actually fix the problem by switching to CP3 pumps leave hundreds of thousands of truck owners still vulnerable to catastrophic failures.
Owners who missed the November deadline face an impossible choice: pay $2,000-$4,000 for a CP3 conversion now, or risk a $15,000 repair bill later (with only 50% reimbursement available until May 2026).
Legal Disclaimer: This information is for educational purposes only and does not constitute legal advice. If you believe you are eligible for compensation related to the GM CP4 lawsuit or have questions about the future repair warranty, consult with a qualified attorney to discuss your specific situation and legal options.
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About the Author
Sarah Klein, JD, is a licensed attorney and legal content strategist with over 12 years of experience across civil, criminal, family, and regulatory law. At All About Lawyer, she covers a wide range of legal topics — from high-profile lawsuits and courtroom stories to state traffic laws and everyday legal questions — all with a focus on accuracy, clarity, and public understanding.
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