Need help!! Freightliner with Cat 3406e got me stumped

What is an "ignition power feed" ?

I have 12v keyed hot, 12v constant, and ground at pins 4, 5 and 6. (40 pin)

Load tested to 10 amps

 

Ok gotcha? Thats same thing the guys at CAT told me

 

Question: where does the signal from the truck come from? And will not having this zignal from the truck keep the ecm from powering up?

The cat guys saud theres a module of some kind in the truck but i dont see one. And ive never seem one in My n14 classic FL either?

 

Yes i jave the 40 pin diagram.

 

Ok,

I have verfied that the hot and grounds are functional with ecm plugged in and key on bu inserting my probe into the baxk of the plug while connected

 

Ive all but ruled out a bad ecm. Its got to be in the truck wiring somewhere...but idk what else to check because i cant fund any more info on how the system works??