After unhooking the battery my radio is not working nor can I see my gas gallons?

The first thing we need to do is check the fuses.

here is a guide and the fuse location in the diagrams below:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If the fuses are okay let's run the codes, you may have a bad PCM.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is how to change the PCM out which you can get a rebuilt unit by searching Google or eBay. Check out the images (below). Please let us know what you find. We are interested to see what it is.