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

1999 CADILLAC DEVILLE

6,000 MILES

ZAYVEONYOBOY47

MEMBER
1 POST

After unhooking battery cables for my car listed above my radio is not working nor can I see my gas gallons and my gear shift lights on the dash are blinking. also, saying I have no PCM etc. data whatever that means if you can help me please!

Jan 15, 2023 at 8:30 AM

STRAILER

✓Experienced Mechanic
55,616 POSTS

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.

Images (Click to enlarge)