I have a Toyota 8FGU25 showing this E 04-1 code & runs terrible at idle. Found & watched a video showing this code - means the engine temperature sensor with 2 wires needs replaced or a wiring issue going to it. I replaced the sensor for $49.00 filled the coolant system & bled it warmed up the engine & still same problem. Next I am going to test the 2 wires going into the plug on this sensor & hoping to find the problem.

04-1 Coolant temperature sensor open abnormality.
The engine may have a problem at low temperatures.