Need help with heating engine

My car is overheating I am getting the code P480. I changed the relay for fan one fan two fan three. I checked the continuity to wires to fan one and fan two. I change the engine coolant temperature sensor and connector wire to engine coolant temperature sensor. I put a brand new thermostat new radiator new hoses change coolant. New motor fan for number one. I even put a new water pump. I drive the car for twenty miles and will not heat up after twenty miles it starts heating up and it's the same routine all the time. Fan number one will stop working. Could I have a faulty engine coolant temperature sensor or could it be the computer.