Fiesta Tire Pressure Fault

Sounds like it could be, especially if the pressure is actually okay. How old are the sensors? They run on batteries, and those don't last forever. Have you tried resetting the system through the car's menu, or does the error pop up again immediately? And does it happen right after starting the car or after driving for a bit?

I haven't reset it, didn't know that was an option. Where exactly would I find that in the menu? And how would I know how old the sensors are? I bought the car used.

The reset function should be somewhere in the car settings, maybe under 'Vehicle' or 'Tire Pressure'. Check your owner's manual. As for the age, if they're original, they're probably reaching the end of their lifespan. Five or six years is about what you can expect. Given all that, and the error code being stored, a failing sensor battery seems likely. Best bet is to take it to a workshop and have them check. They can read the sensor data and tell you for sure which one is faulty.

I checked the manual, found the reset, but the error came back instantly. Took it to the shop as you suggested. Turns out it was indeed the sensor battery. Cost me 280€ to replace. Appreciate the help!