Estimated reading time: 10 minutes.
Key facts
- What happened: On September 30, 2026, U.S. District Judge Laurie J. Michelson certified five state classes of Ford diesel truck buyers who paid out of pocket to repair a failed Bosch CP4 high-pressure fuel pump.
- The case: Droesser v. Ford Motor Co., No. 2:19-cv-12365, in the U.S. District Court for the Eastern District of Michigan. The suit was filed on August 9, 2019.
- The vehicles: Ford diesel trucks equipped with the 6.7-liter Power Stroke engine, which the case calls the Class Vehicles. The class certification opinion describes them as 2011 to 2023 trucks.
- The states: California, Louisiana, Ohio, Pennsylvania and South Carolina. The judge refused to certify proposed Indiana and New Jersey classes.
- Who is left out: Owners whose pumps have not failed, buyers who signed an arbitration agreement with their dealer, and anyone Ford already reimbursed for the repair.
- Status: No trial date, no settlement and no claim form. Certification lets the case go forward as a group lawsuit; it does not decide whether the pump is defective.
In this article
- What the judge decided
- Who is in the certified classes
- What the lawsuit says is wrong with the CP4 pump
- How Ford is fighting the case
- Why some owners and states were left out
- What the summary judgment ruling did
- Timeline
- Who may be affected and what you can do now
- What remains unresolved
- What happens next
- Frequently asked questions
What the judge decided
After seven years of litigation, the lawsuit over the CP4 fuel pump in Ford's 6.7-liter Power Stroke diesel trucks can now move forward on behalf of groups of owners in five states.
In a 60-page opinion issued September 30, 2026, Judge Michelson granted in part and denied in part the plaintiffs' motion for class certification. She certified classes in California, Louisiana, Ohio, Pennsylvania and South Carolina, appointed named plaintiffs from those states as class representatives, and appointed Hagens Berman Sobol Shapiro, Hilliard Law and The Miller Law Firm as class counsel.
The same day, the judge issued a separate opinion on Ford's motion for summary judgment. That ruling narrowed the case by dismissing several named plaintiffs and claims, but it found real factual disputes about whether the pump is defective, whether the alleged defect causes the failures, and what Ford knew. Those disputes are for a jury, not a judge, to resolve.
Two months earlier, on July 28, 2026, the court denied Ford's request to exclude the testimony of the plaintiffs' engineering expert, Dr. Bradley Edgar. Class certification generally requires evidence that can answer key questions for all class members at once, and expert testimony is often part of that showing.
What class certification means Certification lets a few named plaintiffs pursue claims for everyone who fits a court-approved definition. It is a procedural ruling. It does not mean Ford has been found liable or that any money will be paid.
Who is in the certified classes
Each of the five state classes uses the same basic definition. Based on the opinion, a person is in a class if they:
- Bought a Class Vehicle in that state,
- Did not sign an arbitration agreement with the dealership, and
- Have paid out of pocket for a repair to the CP4 fuel pump.
People Ford has already reimbursed for the repair are excluded. The California class is limited further to buyers who purchased the truck mainly for personal, family or household use, which tracks the scope of California's consumer protection statutes.
The certified claims are for breach of the implied warranty of merchantability, which is the legal promise, built into most sales, that a product is fit for its ordinary purpose. Each state's version applies:
- California: the Song-Beverly Consumer Warranty Act, plus a claim under the Consumers Legal Remedies Act, a state law against deceptive practices.
- Louisiana: the state's redhibition law, which lets a buyer recover when a hidden defect makes a product useless or so inconvenient that the buyer would not have bought it.
- Ohio: an implied warranty claim recognized in Ohio tort law.
- Pennsylvania and South Carolina: implied warranty claims under each state's version of the Uniform Commercial Code.
The opinion treats the plaintiffs' California Unfair Competition Law claim as withdrawn.
What the lawsuit says is wrong with the CP4 pump
The CP4 is a high-pressure fuel pump made by Robert Bosch GmbH. It pressurizes diesel before the fuel is injected into the engine. The pump is lubricated by the diesel fuel that runs through it.
The plaintiffs allege the pump's design does not tolerate American diesel. As summarized in the court's opinions, they argue that U.S. diesel is less lubricating than the European fuel the pump was designed around. One measure cited is the lubricity "wear scar" test: the U.S. standard allows a wear scar of up to 520 microns, while the European standard allows up to 460. A larger scar means less lubrication.
According to the plaintiffs, that mismatch can cause internal pump parts to wear and shed metal shavings. Those shavings travel through the fuel system, so a pump failure can damage injectors and other parts and leave the truck unable to run. The court's opinions describe the cost of the repair as roughly $9,000, and the summary judgment opinion notes it can exceed $10,000. In a press release, Hilliard Law said owners have faced repair bills from $8,000 to $20,000.
Certification is not a finding of a defect Every statement about how the pump fails is an allegation that Ford disputes. The court found that the evidence raises questions a jury must answer. It did not decide those questions.
How Ford is fighting the case
Ford denies that the CP4 pump in its trucks is defective. According to the opinions, Ford points to testing by Bosch and by Ford, says the pump design was upgraded over time, and argues that failures can be caused by how a truck is maintained or fueled. Examples Ford raised include ignoring the water-in-fuel warning light, neglecting fuel filters, and putting diesel exhaust fluid or gasoline in the fuel tank.
Ford also relied on contract terms. It argued that a class action waiver in its warranty booklet barred the case from proceeding as a class. The judge rejected that argument because Ford raised the waiver only after about six years of litigation, which she found was too late. Ford also argued that buyers who signed arbitration agreements with their dealers could not be part of the case, and those buyers are excluded from the certified classes.
Why some owners and states were left out
Owners whose pumps never failed. The plaintiffs wanted to include people who own a truck with the CP4 pump whether or not it has broken. The judge declined. Relying on the U.S. Supreme Court's 2021 decision in TransUnion LLC v. Ramirez, she found that owners who had no failure and paid for no repair lacked the concrete injury needed to sue for damages in federal court. The opinion notes that the plaintiffs' own expert estimated that most Class Vehicles would never have a pump failure.
Indiana. The court found the Indiana representative's claim was time-barred, meaning it was filed too late under the state's deadline, so there was no suitable representative for an Indiana class.
New Jersey. The court found the New Jersey representative was not an adequate representative and that his claim was also time-barred.
What the summary judgment ruling did
Summary judgment is a ruling on whether a claim can be decided without a trial because the key facts are not genuinely disputed.
Here, the judge dismissed claims the plaintiffs had abandoned and dismissed the claims of named plaintiffs from Alabama, California (one plaintiff), Indiana, Michigan and New Jersey. She denied summary judgment on the central issues that remain: whether the pump is defective, whether the alleged defect caused the failures, and whether Ford knew about the problem. The plaintiffs who remain, including the California representative whose pump failed in June 2025, can take those claims forward.
Timeline
| Date | Event |
|---|---|
| August 9, 2019 | Droesser v. Ford filed in the Eastern District of Michigan |
| April 28, 2023 | Plaintiffs file their third amended complaint |
| June 9, 2025 | The California class representative's CP4 pump fails, according to the opinion |
| July 28, 2026 | Court denies Ford's motion to exclude the plaintiffs' expert, Dr. Bradley Edgar |
| September 28, 2026 | Court holds a limited hearing on class certification |
| September 30, 2026 | Court certifies five state classes and rules on summary judgment |
| About October 30, 2026 | Deadline for the parties to propose a class notice plan, 30 days after the order |
Who may be affected and what you can do now
You may be a class member if you bought a 6.7-liter Power Stroke diesel Ford truck in California, Louisiana, Ohio, Pennsylvania or South Carolina, paid for a CP4 pump repair yourself, did not sign a dealership arbitration agreement, and were not reimbursed by Ford.
There is nothing to sign up for or file right now. The court ordered the parties to propose a plan, within 30 days of the September 30 order, for notifying class members. Class members in a case certified under Rule 23(b)(3) of the Federal Rules of Civil Procedure normally receive notice that explains the case and gives them a chance to opt out, which keeps their right to sue on their own.
Keep your repair records Class membership turns on having paid for a CP4 repair yourself. Keep repair invoices, tow receipts and proof of payment, your purchase paperwork, and any record of reimbursement from Ford. Check whether you signed an arbitration agreement with the dealer.
For other cases that are open now, see our list of class action cases you can join.
What remains unresolved
- An appeal of certification. Federal rules let a party ask an appeals court to review a class certification order. We did not find a Rule 23(f) petition in the public docket records we reviewed.
- The notice plan. The content and method of class notice had not been approved when we reviewed the record.
- Trial. No trial date appears in the materials we reviewed.
- Owners in other states. The ruling covers only the five certified states. Owners elsewhere are not part of these classes.
- The defect question. Whether the CP4 pump is defective, and whether Ford is liable, has not been decided.
This article is for information only and is not legal advice. The plaintiffs' allegations have not been proven, and Ford disputes them.
What happens next
The parties must propose a class notice plan for the court's approval. Once a plan is approved, class members would be notified and given a deadline to opt out. The case will then move toward trial unless Ford obtains appellate review of certification or the parties settle. We will update this story as the court acts.
Frequently asked questions
What is the Ford CP4 fuel pump lawsuit about?
Owners allege that the Bosch CP4 high-pressure fuel pump in Ford's 6.7-liter Power Stroke diesel trucks is prone to failure with U.S. diesel fuel, which can send metal debris through the fuel system and lead to repairs costing around $9,000 or more. Ford denies the pump is defective.
Which states have certified classes?
California, Louisiana, Ohio, Pennsylvania and South Carolina. Proposed classes for Indiana and New Jersey were denied.
My CP4 pump never failed. Am I in the class?
No. The judge excluded owners who have not paid for a CP4 repair, finding they lack the injury needed to sue for damages in federal court.
Is there a Ford CP4 settlement or claim form?
No. There is no settlement and no claim form. The court has certified classes for litigation, and the parties are working on a plan to notify class members.
What if I signed an arbitration agreement with my dealer?
Buyers who signed an arbitration agreement with the dealership are excluded from the certified classes. Whether a specific agreement applies to you is a question for a lawyer.
Who represents the class?
The court appointed Hagens Berman Sobol Shapiro, Hilliard Law and The Miller Law Firm as class counsel.
