I already replaced the sensor with a brand new one, I checked the voltage from the car and its 5V, and I checked the fluid level and its fine, and its not overheating

I already replaced the sensor with a brand new one, I checked the voltage from the car and its 5V, and I checked the fluid level and its fine, and its not overheating

Did you use the ECM for your ground?
There could be an internal fault that prevents the ECM from "seeing" the sensor properly: the ECM is sending the correct reference voltage but does not recognize the signal when it comes back.

Not yet but I think its OK because I checked the temp with my scan tool and the read ing was normal. So I disconnected the sensor and the temp dropped to -40°c. So I think its reading it. I turned off the light and drive 100 miles before it popped back on, when before it would come on almost right away