The National Traffic Highway Safety Administration (NHTSA) said on Monday it's opened an investigation into the 2015-2017 Ford F-150 over a possible transmission defect. The investigation, first reported by Reuters, is over reports that the transmission could unexpectedly downshift when the vehicle is at highway speed, which could cause a sudden rear-wheel lockup and loss of control. NHTSA received 138 customer complaints, and the investigation covers 1,270,970 vehicles.
NHTSA has no reports of crashes, injuries, or fatalities that could be related to this possible issue. The 2015-2017 F-150 came with Ford's 6R80 six-speed automatic. Last year, Ford issued a recall for the 6R80-equipped 2014 F-150 over a software problem that could cause the transmission to unexpectedly downshift to first. Ford also previously recalled other SUVs with the 6R80 over the same issue. It's unclear if NHTSA's investigations of 2015-2017 F-150s is over the same issue as earlier 6R80-fit vehicles, but the problems do sound similar.
For the 2018 model year, Ford switched the F-150 over to its new 10R 10-speed automatic co-developed with GM. Coincidentally, GM has recalled a number of 10R-equipped vehicles over the last few months. According to GM's NHTSA filing, a control valve could wear out over time, potentially causing harsh downshifts with wheel locking.
Ford has not issued recalls of its 10R-equipped vehicles and there are NHTSA investigations, either. A Ford spokesperson tells Motor1 that GM and Ford use different control mechanisms, so this recall is unrelated to the 6R80 recall.
