Gear vs park idle , no p/n switch

[RFloresjr00]

i have recently swapped a 2001 saburban drivetrain into a 53 truck , performed adjustments in pcm to change from dbw to dbc, all stock except tsp 220r cam and circle d converter 2800

doing this swap I used an aftermarket harness that does not utilize the prndl or a p/n switch

everythkng works as as should and drives good

problem im having is in physical p/n idle is great 675/700 but when i put in in physical gear or rev engine rpm goes up couple hundred and pushes against the brakes making it uncomfortable at stop lights

my understanding is when there is no p/n switch it uses (gear) tables for idle and airflow references if this is wrong pleas let me know..

how can i get this engine to maintain approx. 700rpm in physical gear like it does park, also what tables does it read differently when switching from gear to p/n when it is only reading signals from transmission ?

[matty b]

The transmission has an internal pressure switch that knows what gear the transmission is in save for Park and Neutral so it lists them as P/N. The external switch is used for gear indicator on the dash, neutral safety and reverse lights.

[RFloresjr00]

Ok so under Prndl do I leave it as none since I don’t have a selector switch or does it need to be prndl or p/n

[matty b]

leave it to none