Could it be a code ????

Hello my name is Tom I own a 1994 348 spider there has been a few times now when I have started the car to warm it up, I first get a E1 displayed where the temp indicator is in the center console but no temp showing. After the car has warmed up in the same area E5 shows
Still no temp reading. I think it my be the thermostat, what do you guys think? Any thoughts would be very helpful. I am a virgin both with the car and on the board, thank you all very much.....Tom

 

Thank you for your input it was very helpful. Tom