After having the battery jumped with the donor battery cables on backwards, there are multiple accessories not working and it will not start?

Yep, they don't like it when the battery is connected backwards, it sounds like the BCM when out, but we should start by checking the fuses.

Here is a guide to help and the fuse locations as well:

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

Here are the fuses for the ALDL connector so we can see if the scanner plug has power, also I would try a CAN scan, you can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

here is a video to show you how:

https://youtu.be/u-4syLc-ifQ


Check out the images (below). Please let us know what you find.

Hey Ken, I appreciate your response. I know how to access 6 of those fuse boxes. The one in the trunk, the one on the battery, one on the driver dash, one on the passenger side dash, one in the engine bay by the ECM and one where the positive jump terminal is. The others like the j519 I’m having issues finding. Would you be able to show more details as to where and how to get to them?

This is all they gave me on this, did you do the CAN scan?

I have two CAN scanners. OBDeleven and Carista and neither can connect so I just checked the fuses and relays. I found all of the relay/fuse boxes from alldata. I checked all the fuses, and they all have power in the on position except one I drew an arrow to in the pic I’ve attached. It’s a 5amp mini in the engine relay/fuse box. I took it out and tested the socket itself and no power. I took a working 5amp mini and put it there just to check and it wasn’t getting voltage. I bench tested all the relays by attaching mini alligator clips from the battery to the coil prongs to see if they click when power is sent, and they did. Then while the clips were attached to the coil prongs, I checked the resistance from the output prongs, and they were at almost 0 so they’re good. I'm not sure what would cause that one fuse socket to not get power.

It may only have power in particular situations, what did the CAN scanner come up with?

My scanners still won’t connect to the obd2 port. I thought that also about the fuse only turning on in certain switch positions, but Alldata shows it’s connected to terminal 87(I’ve attached a pic) I believe the non-working fuse is fuse 9. I tested every other fuse in that box with the ignition in the on position and all of them have power and all those other fuses are terminal 87 too. I also attached a circuit diagram for fuse 9(sb9). I can trace it to the ground but I’m not sure what else to make of that diagram. Would the ECM be the issue?

It sure sounds like the PCM is bad, you can remove it and send it out to be tested. But I included the PCM wiring diagrams so you can test the fuses that run the system to make sure the PCM is getting power.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Please let us know how it goes.

anything?