Legal Setback for CARB in Clean Truck Partnership Dispute

California’s aggressive push toward zero-emission vehicle (ZEV) mandates hit a significant roadblock on November 1 when U.S. District Judge Dena Coggins issued a preliminary injunction halting enforcement of a key 2023 ZEV agreement between the California Air Resources Board (CARB) and truck manufacturers.

The Clean Truck Partnership, signed last year, aimed to lock major truck makers into ZEV sales targets ahead of federal timelines. But the agreement’s enforceability was challenged after CARB filed a separate state court lawsuit seeking to compel compliance, undercutting its own claim that no harm would come from letting the deal stand while legal questions played out.

Judge Coggins, a Biden appointee, highlighted this contradiction in her ruling, stating that CARB’s new legal action effectively voided its prior argument that an injunction was unnecessary. Her decision temporarily blocks CARB from forcing manufacturers to adhere to the sales terms outlined in the agreement.

While the injunction is a clear win for the manufacturers, it’s not a total loss for the state. Coggins rejected industry claims that the agreement violated free speech rights or imposed unlawful certification requirements. For now, truck makers only need to show they’ve received federal emissions certification when selling vehicles in California.

The decision adds to growing uncertainty around CARB’s regulatory authority and highlights tensions between California’s climate ambitions and federal legal boundaries.

This is a reminder to all industry leaders that regulatory battles over electrification are far from settled, and that courtroom strategy matters as much as carbon strategy in shaping the future of heavy-duty transportation.