The contact owns a 2019 Ford F450. The contact stated that when the vehicle was started, the check engine warning light illuminated. The contact stated that while driving at an undisclosed speed, the vehicle went into LIMP Mode. The vehicle was taken to the dealer where it was diagnosed and determined that the diesel particle filter (DPF) had failed. The sensor was replaced. The contact stated that the failure persisted. The vehicle was taken back to the dealer. The sensor had been replaced four times. The manufacturer was made aware of the failure and referred the contact to the NHSTA Hotline for assistance. The approximate failure mileage was 19,000.