Quote Originally Posted by ferocity02 View Post
Because it works well enough for me without the clutch switch hooked to the PCM, no need to add complexity to the tune either.

The question here is if a manual tune does use P/N tables when the clutch is depressed or when it's in neutral, why are the idle P/N tables zeroed out in stock manual tunes? And why does it use the P/N throttle follower tables but no other P/N tables? My truck is clearly using the In Gear tables for some things, and the P/N tables for others. At this time, and without further understanding, I don't see how adding the clutch switch will help this.

I also don't understand how the PCM knows when the trans is in neutral, other than the clutch being depressed, or if VSS is 0 and RPM is > 0.
What I was trying to say is you are adding complexity to the tune by not wiring it up like GM did. You are spending loads of time troubleshooting issues that simply wouldnt exist if you connected the CPP to the PCM. It is great that it is working without it hooked in, but I think you're running in circles trying to figure out a way around a simple issue that is easily remedied. To me, the easiest way to find a solution would be to run the wires to the PCM from the CPP and any other sensor that a factory manual truck would have so it is exactly like GM would have wired it. Then start with all of GM's stock settings for a 4.8L manual (only one I know that came with a manual) and start tweaking from there.

I do not know exactly how the PCM determines gear with a manual trans, I think Joe posted about it a week or two ago. I believe it is a combo of RPM and VSS, but dont quote me on that.