Ford Motor Company is recalling nearly 1.4 million F-150 pickup trucks in the United States after federal regulators identified a transmission defect that can cause sudden, unintended downshifts.

Why it matters: The F-150 is America’s best-selling vehicle. A defect affecting this many trucks on the road poses a significant safety risk to drivers and other motorists.

The defect

The recall covers 2015-2017 F-150 models equipped with the six-speed automatic 6R80 transmission. An intermittent signal from the transmission range sensor to the powertrain control module can trigger a sudden downshift into second gear while the vehicle is in motion.

The abrupt gear change can cause a loss of vehicle control. Ford told the National Highway Traffic Safety Administration it is aware of one crash and two injuries potentially connected to the issue.

The fix

Ford dealers will update the powertrain control module calibration software at no cost to owners. The company will begin sending interim notification letters in late April. Final remedy letters will follow in July.

The affected trucks were produced between 12 March 2014 and 18 August 2017. Owners can check their vehicle identification number on the NHTSA website to confirm whether their truck is included in the recall.

Scale in context

This is one of Ford’s largest recalls in recent years. The 1.39 million vehicles affected represent roughly three model years of F-150 production. Ford sold more than 750,000 F-Series trucks in 2016 alone, making the pickup line the backbone of the company’s North American revenue.