No communication with pcm or fcm

It’s ironic that here I am asking questions, when it
was me a few years back answering other peoples.

Well here is my dilemma, My friends 05 Chrysler
T&C has a crank no start with no spark condition.
When I plug in my scanner, I have communication
with all modules except pcm and fcm. I’ve checked
all power and grounds going to pcm. Load tested
them with a headlight bulb. I’ve removed and
disassembled the ipm and cleaned all connectors.

While digging around and checking sensor supply
voltage and ground, I discovered that the wires
leading to the map sensor had lost their insulation
under the p/s reservoir. I was sure I’d figured it out.
Nope…  tried a second pcm…. Nope…. I don’t
understand why I don’t have communication with
pcm, if I short bus wire at pcm to ground and it
takes down the bus, but no communication with
pcm????? I’m game for any suggestions….