The National Highway Traffic Safety Administration has initiated a formal engineering analysis investigating approximately 2.2 million Honda vehicles following widespread reports of engine restart failures, according to an announcement released Friday. The federal safety agency’s Office of Defects Investigation has documented 1,384 consumer complaints regarding vehicles failing to automatically restart after the Auto Idle Stop feature activates at traffic signals and intersections.

Despite Honda issuing a technical service bulletin in January 2023 outlining a two-stage remedy for the defect, NHTSA continues receiving complaints from vehicle owners who have already received the manufacturer’s countermeasures. The engineering analysis represents an escalation in the investigation process, focusing on potential safety defects while gathering additional information about Honda’s service campaign effectiveness.

The investigation encompasses multiple Honda models, including 2016-2025 Pilot SUVs and 2020-2025 Ridgeline pickup trucks. NHTSA documentation references four incidents involving crashes or fires potentially linked to the defect, with two resulting in reported injuries. This investigation highlights the intersection between automotive safety regulations and potential manufacturer liability for design or manufacturing defects.