NHTSA Investigating 1.3 Million Ford F-150s with Faulty Transmissions That May Lock the Rear Axle

The National Highway Traffic Safety Administration opened an investigation into nearly 1.3 million Ford F-150 pickup trucks for a potential issue involving the automatic transmission. According to documents filed with NHTSA, the investigation covers 1,270,970 F-150s from the 2015, 2016, and 2017 model years.

Opened on January 30, 2026, NHTSA's investigation focuses on trucks equipped with Ford's 6R80 six-speed automatic transmission. According to the investigation documents, Ford identified the issue as related to a signal loss in the Output Shaft Speed (OSS) sensor due to degraded electrical connections in the lead frame, causing additional signal loss to the Transmission Range Sensor (TRS).

According to NHTSA documents, signal loss from the TRS can cause the transmission to shift to neutral, upshift, or downshift unexpectedly. The shifts are regulated by a "shift map" from Ford, with the maximum allowable downshift at speeds between 35 and 64 mph programmed to allow the transmission to shift into second gear. The "shift map" is designed to represent worst-case scenarios for the involved vehicles, with Ford acknowledging that the downshifts may cause the rear wheels to lock temporarily.

NHTSA's Office of Defects Investigation identified more than 300 questionnaires filled out by owners of affected trucks, with more than 40 percent reporting at least one wheel lockup event caused by the transmission downshifting.

Ford claims in the investigation documents that the OSS sensor failure in this investigation is different from a previous OSS-related failure that resulted in four recalls covering 2011–2014 model year F150s.

Additionally, preliminary testing from the NHTSA's Vehicle Research Test Center has shown that one possible side effect of the TRS cutting out is a change in vehicle direction. Specifically, the investigation document points out that a vehicle reversing up a hill may suddenly shift into neutral, causing the truck to roll forward.