Ford is recalling 490,574 Super Duty trucks in the United States because their carpets and insulation can catch fire during a crash, according to filings with the National Highway Traffic Safety Administration. It's the same defect as the 1.6 million F-150 trucks that Ford recalled in September 2018.
As with those 2015–2018 trucks, the seatbelt pretensioners mounted in the B-pillars of 2017–2019 Super Duty pickups can generate "excessive sparks" when they activate in a crash. Pretensioners, which deploy in sync with a vehicle's airbags, use a small explosive charge that removes all slack in the belt mechanism during a collision. They're mounted either the behind the B-pillar next to the retractor (which pulls the belt inward) or within the buckle latch next to the seat (which pulls the belt downward). On the Ford trucks, the pretensioner's sparks can ignite the exhausted gas and set the insulation behind the B-pillar and the carpet below on fire. The issue affects all F-250, F-350, F-450, and F-550 trucks built between October 8, 2015, and October 29, 2019, according to the documentation.