Yet another 2nd Gen Camaro - Project/update

[gerno]

I don't believe it's part of the PSI harness. I've found they left multiple things out. I believe the neutral safety would only disable the starter. I'm using the harness from the car to engage the starter so it doesn't impact it. This is what I think the issues with terminal 52 is. 52 is the starter enabler relay and based on what I see on LS1 tech with others who have similar issues if you don't ground that wire then it will crank and not start. I think the ECM uses it as a safety.

After typing all that it seems you are on the same path. Perhaps pin 52 does work with the neutral safety circuit. I'm learning quickly but not enough of an expert to know.