General Motors Offers Truck Owners $12,000 Payments in Fuel Pump Settlement

What’s the Problem
Owners of heavy-duty trucks from General Motors LLC may be facing expensive and catastrophic engine damage due to a defective high-pressure fuel pump known as the Bosch CP4. Specifically, certain 2011–2016 model year trucks equipped with the 6.6-litre V8 LML Duramax diesel engine (in the Chevrolet Silverado HD and GMC Sierra HD) allegedly contain a CP4 pump that isn’t compatible with U.S. diesel fuel lubrication levels. As a result, the pump may run near dry, produce metal shavings, deposit debris throughout the fuel system and engine, and cause sudden failure.

Allegations
Plaintiffs in the class-action lawsuit assert that GM knew or should have known that the CP4 pump was incompatible with U.S. diesel fuel conditions, including lower lubricity, and that the pump would suffer premature failure. The defect allegedly leads to fuel system contamination, catastrophic engine or injection system failure, and repair bills reaching up to $15,000. Truck owners claim GM sold the vehicles despite this defect and failed to sufficiently warn them. The legal action led to a settlement valued at roughly $50 million, covering cash payments for out-of-pocket repairs and extending limited future warranty coverage.

Recall/TSB
There is no widely published full-vehicle recall specifically for this CP4 fuel pump issue (at least in publicly available data). However, trucks that meet the class‐settlement criteria are covered under the terms of the settlement in the case Chapman v. General Motors LLC (Case No. 2:19-cv-12333-TGB-DRG) which received final approval in May 2025. The settlement applies to owners of 2011–2016 Chevrolet Silverado or GMC Sierra (6.6L Duramax diesel) trucks, purchased from March 1, 2010 through September 13, 2024, from authorized dealerships in the states of California, Florida, Illinois, Iowa, New York, Pennsylvania and Texas. If you believe your truck falls into this category, you should check the settlement website to verify eligibility via VIN lookup.

Symptoms
Owners of affected trucks may experience the following warning signs:

  • Unexplained engine warning lights or fault codes related to fuel-system or injection issues

  • Sudden loss of power or stalled engine without prior warning

  • Unusual engine noise or rough running after repair of fuel system (indicative of metal shavings contamination)

  • Higher than expected repair costs for fuel pump or injection system components (exceeding typical wear and tear)

  • Multiple visits to the dealership or repair facility, especially for fuel-system components

Because the CP4 pump allegedly deposits metal debris throughout the system, even replacing the pump may not prevent further damage unless the entire fuel rail, injectors, and associated components are cleaned or replaced. This makes the situation particularly costly and risky.

How to Proceed

  • Document Issues: Keep detailed records of all repairs and communications with GM or your dealership. When you drop your vehicle off for service, ensure your complaint (e.g., “fuel pump failure,” “metal shavings in fuel system”) is noted on the work order you receive.

  • Reasonable Number of Repair Attempts: While the law doesn’t specify an exact number, if the same problem (fuel pump failure/injection system damage) persists after four or more repair attempts, or if the vehicle has been out of service for more than 30 days cumulatively, it may qualify as a “lemon.”

  • Monitor Symptoms: Any new engine warning lights, abnormal noises, or loss of power? Stop driving if you suspect major fuel system problems and have the vehicle inspected — especially if you’ve already had the pump replaced and issues persist.

  • Check the Settlement Eligibility: Even if you’ve already paid for a repair of the CP4 pump in an eligible truck, you may still qualify for a cash payment or extended warranty coverage under the GM settlement. Submit your claim if you paid out of pocket for a repair before May 6, 2025.

  • While the settlement offers compensation, it does not preclude consulting your attorney: Especially if your situation involves catastrophic engine failure or your vehicle no longer qualifies under the settlement parameters, you may still have legal avenues under state or federal consumer protection laws.

Protect Your Rights Under California Lemon Law

Unfortunately, General Motors has taken advantage of California’s “new” lemon law, AB 1755 and Civil Code section 871.20 et seq. Because of these changes, vehicles purchased in California more than six years may no longer qualify for lemon law protections. If this concerns you, consider contacting your local state representative to express your disappointment that California’s lemon law has been weakened. Senator Tom Umberg was critical in this erosion of California consumer rights, along with Assembly Member Ash Kalra. You can contact them below:

https://sd34.senate.ca.gov/contact

https://a25.asmdc.org/contact-ash

https://www.gov.ca.gov/contact/

Joshua ValeroGM CP4 fuel pump defect, Duramax diesel CP4 lawsuit, Chevrolet Silverado HD fuel pump failure, GMC Sierra HD CP4 fuel pump, California Lemon Law GM diesel truck, GM heavy-duty diesel fuel system metal shavings. Meta description: Learn about the CP4 fuel pump defect in 2011-2016 GM Duramax diesel trucks, how it causes engine damage, and your rights under California Lemon Law.