Temperature gauge not working and car overheated

Let's start with the ECT sensor issue. I suspect this is most likely a faulty sensor. However, we need to figure this out and then address the other issues as I doubt they are related. In fact the ECT issue is probably not related to the overheat as it wouldn't make the engine overheat.

So we need get a little more detail about these issues. Was this vehicle sitting for a while? Was there more to this or was the vehicle driving fine just before this and you decided to change the battery?

Let's start with this info and we can go from there. Thanks

Yes, car was sitting for a few months I believe. When jump started car I did it from battery under seat, I was un aware to jump from fuse box and negative post. I don't believe fans are working. It will not overheat when on highway. It was driving fine for the week before I jumped it. Also it says check coolant level no matter if it's full or not. Thanks

Okay. I don't think all this is related. I suspect you just have a number of different issues. So let's tackle the ECT with the info I attached before and go from there.

The only way that this could be related is if a mouse or something go under the hood and chewed some wires. It would be worth looking around most of the harnesses. If not, let's tackle the coolant temp and then we can start a new post on the other issues because the coolant light being on is just a level sensor. So all these put together and it may be chewed wires.