The U.S. National Highway Traffic Safety Administration (NHTSA) has launched a preliminary investigation into nearly 1.3 million Ford F-150 pickup trucks following reports of unexpected gear downshifts. The issue, which can cause a temporary rear-wheel lock-up, raises concerns about potential safety risks.

The probe covers F-150 models from recent years, with some drivers reporting sudden shifts to lower gears while driving. The NHTSA will assess the scope and severity of the problem to determine if a recall or further action is necessary. Ford has yet to comment on the investigation.