Ya gotta get a Turbo 500 still.... that'll ease up your EFI Live....
Ive done many e38 T42 conversions here in Australia, but I get my fair share of problems with them.
Firstly, this combo was available in the first 6L 2004/5 VZ Commodore but only with 4L65e, which is easy to modify the harness so that the 4L80e will run on a 4L60e tune.
We also, in the same year models have a HSV version using the LS2 engine with 4L60e with T42
Not all T42's are the same....
It will only work with matching PCM and TCM's and O/S's
We do not have TUTD for these, but am keen to know if its possible....
6L80e's have the Park Neutral switch inside the trans, which feed from pin 3 on the trans plug to X1-01 and this wire also branches off to the start relay ground.
The 4L60e has this wire in the selector switch assembly on the side of the trans on the selector shaft... (at least they do here is Oz), and the 4L80e doesn't have this that I have seen anyways...
So ideally, you need to run this grounding wire through your PK/N switch to ground, and also on the ecu side of switch, to the start relay for it to function properly.
But for now, just try grounding pin X1-01, also something to watch here, is that this is grounded before turning key on, otherwise this gives a no start as well.
With the start circuit and relay, you must have everything such as canbus and all trans wiring perfect because the ecu will no give the all clear to the start relay to turn on.
I eliminate this circuit in conversions because of this, and switch depress clutch off and disable start diagnostic as well as switch to ground in the software.
I may still have the diagrams for T42 e38, but not sure if they will work in your Pontiac (VE Holden Commodore), because the ecm you use wont match your bcm, hence xmas tree on dash...
The big problem with these early e38 OS is they seem to be very reliant on the other onboard ecu's and seem to spit the dummy really easy.
Personally, I would stay with the 6L80e, as they are awesome, once you get your head around tuning them for hp