The contact owns a 2015 Ford F150. The contact received notification of NHTSA Campaign Number: 26V237000 (POWER TRAIN). The contact stated that while driving at an undisclosed speed on the highway, the vehicle unexpectedly downshifted to a lower gear, and an abnormally loud noise was heard from the vehicle. In addition, the vehicle failed to accelerate as intended and was rear-ended from behind. No injuries were reported. No police report was file. The engine revved up; the rear tires made an abnormal grinding noise. The contact was able to pull to the side of the road. The powertrain warning light and lamp wrench warning light were illuminated. The contact stated that when the vehicle was started, the engine revved up, and the vehicle failed to accelerate past 35 MPH. The other driver assisted the contact and helped tow the vehicle back to the residence. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The vehicle remained in the residence unrepaired and had not been driven since. The manufacturer was not notified of the failure. The failure mileage was approximately 144,000.