Tcm pcm no communication?

So the first thing to do is check the battery voltage, it needs to be above 12 volts. If not the computers will not turn on, this guide can help you with the test.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

If the voltage is okay, I would next check all fuses with the systems on to help check for power as well.

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

U0100 - Lost Communication With ECM/PCM

Under-hood fuse box:

1. IG MAIN
2. FI MAIN
3. PCM/ECM fuse
4. Starter cut relay

I’ve seen cracked 30A FI fuses cause exactly this. Please go over these guides and get back to us.