The contact owns a 2017 Ford F-150. The contact stated that while driving approximately 55-60 MPH, the transmission unexpectedly downshifted to first gear, causing the rear wheels to lock up. The check engine warning light was illuminated, and the wrench symbol was displayed on the instrument panel. The vehicle went into LIMP Mode, and the vehicle was slow to respond. The vehicle was turned off for ten minutes and then restarted. While driving approximately 25-30 MPH, the failure recurred. The contact stated that DTC: P1702; indicated an intermittent failure with the transmission range sensor circuit (PRNDL sensor), potentially causing erratic shifting or even the vehicle entering LIMP Mode. The local dealer was contacted, but the vehicle was not diagnosed or repaired. The manufacturer was contacted and opened a case, and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 108,700.