E38 stand-alone start/neutral relay integration

Anyone out there swapping gen 4?s ever try using the neutral safety relay? Pin 52 of the J1 yellow/black seems to send a ground signal to the start relay (allowing starter control for park/neutral) with a auto trans. This is the first swap that I?ve tried this (no pnp on the column). I have all the schematics and checked and re-checked and can?t see why it would not work. I have this setup in a stand-alone (e38) with the A6 (6L80E) :it does not have a external range switch:. Not sure what I?m missing but it?s not sending a ground signal (allowing the relay to trigger) even though I can see trans range on the scanner and everything says go. Crossing it out allowed the engine to start. Don?t know if the PCM is looking for another input from the BCM or not or if it something I?m missing in the tune or..... it?s not possible. Any input would be appreciated. Surely someone has went through this already.
Excellent info on here folks.
Thanks