• The NHTSA’s Office of Defects Investigation (ODI) is shining its spotlight on Ford’s F-150.
  • Some 2015-17 model-year pickup are making unexpected downchanges.
  • Around 1.27 million trucks with the six-speed auto are caught up in the safety probe.

The smartest modern automatic transmissions are so clever they seem to know to shift down before you’ve even realized you needed a lower gear. But Ford F-150s are choosing to swap ratios at entirely the wrong time, and now regulators have opened a probe to examine a problem that could affect almost 1.3 million trucks.

The National Highway Traffic Safety Administration’s (NHTSA) Office of Defects Investigation (ODI) is putting 2015-2017 model year Ford F-150s under the microscope after receiving 138 complaints from drivers who say the trucks are making unexpected and definitely unrequested gearchanges.

Related: Ford Wants Judge To Toss Out $2.5 Billion F-150 Roof Safety Verdict After Alleged Jury Bias

The downshifts are happening without any prior warning, and at highway speeds, which means they could be more than confusing and annoying. Some drivers report that the shift doesn’t only result in the truck slowing, but can lock the rear wheels up dangerously. In bad weather the effect could be like crossing one of those kickplates at a driver training center designed to launch a car sideways. But a lot less fun.

Though the ODI’s report doesn’t state the specific transmission in this case, we know Ford introduced the 13th generation F-150 for the 2015 model year, but the automaker’s 10-speed automatic didn’t arrive on the truck until MY18. That suggests the affected pickups all have the older six-speed auto.

 Feds Investigating 1.3 Million F-150s Over Random Downshifts

An estimated 1,270,970 trucks are covered by the ODI’s preliminary investigation, which will look into the problem and decide if a full-scale engineering analysis is needed. If that happens and testers find fault with the transmission or its control unit Ford could be required to recall all of those trucks. And that wouldn’t be a quick Tesla-style OTA fix, but would mean owners returning to dealers.

Earlier this month Ford announced a recall for thousands of F-150 trucks due to a software issue that prevented electric or electric-over-hydraulic brakes on towed trailers from functioning properly. The fix for the recall, which also affected the brand’s Super Duty trucks as well as the Maverick, Expedition and Lincoln Navigator, involves rolling out a new integrated trailer brake control module software.

 Feds Investigating 1.3 Million F-150s Over Random Downshifts