# GM Duramax CP4 Fuel Pump Settlement

General Motors LLC settled allegations that the Class Trucks had a defective high-pressure fuel injection pump known as the CP4 pump, that the pump is unreasonably fragile and prone to catastrophic failure, and that GM knowingly concealed this defect. General Motors LLC denies any wrongdoing and the court made no finding of liability.

A settlement over an alleged defect in the CP4 high-pressure fuel injection pump fitted to model year 2011–2016 Chevrolet Silverado and GMC Sierra trucks with a 6.6L Duramax diesel engine, bought from GM-authorized dealers in seven states. The claim filing deadline of November 6, 2025 has passed.

| Field | Detail |
| --- | --- |
| Defendant | General Motors LLC |
| Total settlement | $35,000,000 |
| Estimated payment | The official site describes two funds. A $30 million Repair Fund paid Class Members who paid out of pocket for a CP4 repair that was not covered by warranty; the site states the payment depends on how many valid claims are received and could range from $6,356 to $12,712. A $5 million Former Owner Fund paid Class Members who no longer own their trucks and did not pay out of pocket for a repair; the site states that payment could range from $400 to $800. |
| Claim deadline | 2025-11-06 |
| Who is eligible | People who bought a model year 2011–2016 Chevrolet Silverado or GMC Sierra equipped with a 6.6L Duramax diesel engine from a GM-authorized dealer in California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas from March 1, 2010 through September 13, 2024. |
| Proof required | A claim required proof of purchase — such as a purchase agreement or financing documentation showing the claimant's name and the name and address of the GM-authorized dealer — plus proof of repair. Former owners who sold the truck before May 6, 2025 and did not pay for a repair had to submit proof of sale instead. |
| Official claim site | https://www.gmfuelpumplitigation.com/ |

To claim, follow the link to the official site and file there. We never file for you.

## Sources

Verified 2026-07-30.
- Official Settlement Website — Chapman, et al. v. General Motors LLC, Case No. 2:19-cv-12333-TGB-DRG (JND Legal Administration, 2026) — https://www.gmfuelpumplitigation.com/

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This information is not a substitute for legal advice.