— An investigation into Ford F-150 downshift problems has been closed based on recalls of F-150 trucks.
The first Ford F-150 downshift recall was issued in September 2016 for 2011-2012 trucks equipped with 6-speed (6R80) automatic transmissions.
The Ford F-150 downshift recall followed owner complaints about transmissions that suddenly downshifted into first gear causing the rear wheels to lock up.
Ford engineers said the F-150 sudden downshift was caused by intermittent signal loss from the transmission’s output shaft speed (OSS) sensor due to solder joint cracks on the OSS circuit board.
But in December 2017, the National Highway Traffic Safety Administration opened a "recall query" to determine if the repairs fixed the F-150 downshift problem. Ford then issued a downshift recall for more than 1.2 million trucks.
Ford said dealers would reprogram the powertrain control modules to prevent unintended downshifting, but issued another recall in June 2019 because previous repairs didn't stop the trucks from downshifting.
The government opened another investigation into the F-150 downshift recall in March after receiving at least 85 complaints about sudden downshifts into lower gears in 2014 Ford F-150 trucks.
This caused Ford to announce an F-150 downshift recall in June for 2014 Ford F-150 trucks.
By May, Ford was aware of 2,184 reports about unintended transmission downshifting and rear wheel lock-up events, 1,441 warranty claims and 743 reports from consumer complaints, field reports, consumer surveys and lawsuits/legal claims.
"Of the 1,441 warranty claims, 551 warranty claims involved repair of the molded lead frame (38%) and 509 warranty claims involved repair of the control assembly transmission main (35%)." — NHTSA
Safety regulators say they will keep their eyes open for future problems, but for now the investigation is closed based on Ford's actions.
