A number of things can send the engine into derate mode, and I’ll leave that to those here more knowledgeable.
But one easy thing to check first is the fluid level in your radiator expansion tank. The tank should be right of center in front of you as you open the engine hatch. A hose leak somewhere or in the tank itself can take fluid below the tank’s sensor, seen I believe on its right side, triggering a low coolant reaction. The plastic (Ford?) expansion tank has a history of failure.
When our coach was months old, the tank’s hose to the radiator cracked just below the tank, and derated us on I-5. We were ironically on our way to Monaco Harrisburg for another repair under warranty, and only needed towing maybe 20 miles. The faulty hose turned out to not be as new as the coach... go figure.
Joel