NHTSA expands investigation into 2015-2017 Ford F-150 trucks

Federal regulators have intensified their review of more than 1.2 million Ford pickup trucks after the number of complaints about abrupt transmission downshifts rose sharply, officials confirmed.

According to the National Highway Traffic Safety Administration, the inquiry now covers roughly 1,270,970 Ford F-150 vehicles and was officially expanded on Friday, Jan. 30. The agency initially launched a preliminary review in March 2025 after receiving reports about transmission behavior.

The investigation focuses on F-150 models from 2015 to 2017 equipped with the 6R80 transmission. Since the review began, NHTSA has logged 329 driver complaints, a significant increase from the 138 reports previously on record.

Owners described situations where their trucks unexpectedly shifted into lower gears, sometimes dropping straight into first or second without any warning. NHTSA noted that about 43% of those affected experienced rear-wheel lockups during these events, with tires squealing, skidding, or briefly losing traction, leading to momentary loss of vehicle control.

Several drivers said the problem happened multiple times, prompting some to stop using their trucks altogether due to safety worries. Investigators also discovered that 114 vehicles had already undergone transmission-related repairs, including work on the molded lead frame or valve body assembly.

Ford informed regulators that this issue is not the same as transmission defects tied to earlier F-150 recalls. The company explained that the cause may be gradual wear in internal electrical connections, which can interrupt signals from the Transmission Range Sensor.

Ford added that when this signal is lost, it can result in unintended gear changes, such as sudden downshifts or shifts into neutral. In certain situations — particularly at speeds between 35 and 64 mph — the most extreme case could involve a rapid drop from sixth gear to second, sometimes accompanied by temporary rear-wheel lockup.

NHTSA testing also revealed another possible risk when vehicles are in reverse. If the signal failure occurs while backing uphill, the truck may slip into neutral and roll forward, unexpectedly reversing direction.

So far, the agency says the downshifting problem has been linked to only one reported crash.