The control don't know what the temp is inside the oven. The probe called a sensor is responsible for that department. It has properties in it that change in resistance as tempts change. If it goes out then the control don't know what the temp is and declares an error. F-3 is pretty standard for a bad sensor in most American ovens.
According to the tech sheet on this puppy the temps exceeded 575f in cook mode.
The recommendation is to check the sensor connection and check it to read 1080 ohms at room temp. If the sensor ain't shorted and is in spec then yall probably have a stuck relay on the control board.