Fuel Cooler
WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The fuel cooler is a liquid-to-liquid cooler that cools excess fuel being returned to the fuel control module from the fuel rail. The fuel cooler cools unused fuel that the high pressure fuel system returns to the diesel fuel conditioning module. Two fuel hoses and two coolant hoses connect the fuel cooler with other system components.