Plaintiffs Danny Harrison and 38 other named plaintiffs allege that their GM vehicles, ranging from model years 2014 to 2021, suffer from a Valve-Train Defect that causes engines to misfire, stall, surge, or lose power while driving. The complaint also cites ticking noises, chirps, squeals, and squeaks as evidence of the malfunction.
On December 15, 2025, the four-year anniversary of the case, Plaintiffs moved to sever their claims based on the type of cylinder deactivation technology in the vehicles. They sought to split the case into two separate tracks: one for vehicles with Active Fuel Management engines and another for those with Dynamic Fuel Management engines.
Judge Laurie J. Michelson denied the motion on February 17, 2026, noting that while the Court had previously identified three separate part failures and suggested discussing severance, the timing of the request was surprising given the four-year history of the litigation.
The Court applied the five-factor test under Federal Rule of Civil Procedure 21, focusing on whether the claims arise from the same transaction, present common questions, facilitate settlement or judicial economy, avoid prejudice, and require different witnesses or proof.
Regarding judicial economy, GM argued that splitting the case would waste four years of litigation and multiply work for all parties, resulting in two separate sets of expert discovery, summary judgment motions, Daubert motions, class certification briefs, pre-trial proceedings, and trials. The Court agreed that it was hard to see how settlement or judicial economy would be facilitated by severance.
The Court also rejected the argument that severance was necessary to avoid jury confusion. Citing precedent, the Court noted that any potential for prejudice could be mitigated through careful jury instructions, and that single trials generally lessen delay, expense, and inconvenience.
Finally, the Court found sufficient overlap in witnesses and documentary proof to keep the claims together. Although AFM engines contain a component not present in DFM engines, GM contended that the same engineers work on both, and the Court agreed that the overlap justified a single case.