XLR8NSS

iTrader: (4)

We need some wiring diagrams and pinouts in here.

niugnep

Got that right!! Waiting on manuals, and I have bugged my friend at GM from time to time with this stuff but hate to bother him all the time (just had a big thrash with mirrors/switches/panels/modules)and wear out my welcome, so to speak...

niugnep

Looking at some info tossed my way, found this of the tranny pass through connector pinout (n two parts as page was too long to take single picture) Might help,might not. Also seems like the BCM does have some inputs/outputs for the tranny too (shift level, brake pedal, things like that).

There is a speed signal generated inside the tranny, but it is sent as CAN signal looks like. Board will only allow 100k pics so if you need better pm me with e-mail address and I'll try to help out...this new stuff is a big leap it seems, modules everywhere and programming needed for everything...

Wide Open

The connector out by the ECU connection, which I originally thought was for a TCU like the 4L60s, actually turns out to connect to another harness up under the electrical center under the hood. That harness runs through the firewall and connects to the electronic pedal as well as other things I haven't figured out yet. The pics that niugnep posted are the transmission side connection. There are no other external outputs on the transmission or the transfer case so all referenced signals pass through that single connector.
Of interest to the NNBS owners, the ECU and electrical center connections are identical between the 4.8/5.3/6.0 trucks and the 6.2 trucks. The only difference is in the engine/transmisison harness which plugs right into the body.

Wide Open

Just swapping to the 6.2L would be pretty easy. You may need to change the engine harness and ECU as well as your motor mounts. The transmission bellhousing may also need changed to match up to the V8. Everything else would bolt-up from what I can tell. You already have DBW and returnless fuel lines right?

niugnep

So the 6.2L/6 speed auto would drop into my 07...I've already confirmed all the new trucks have the same BCM so could be programmed for the combo looks like (ie for inputs and also for driver range display). Would have to have some kind of manual shift setup, really don't like the denali one on the shift handle, kinda awkward.

Another option would be six speed only, behind the 5.3 would be pretty respectable improvement. ECM would need tuning of course, wonder how plug and play that would all be.

Do you happen to have the connector ID number for the one on the firewall?

Real question is, why won't GM just let us order this in the first place?

Wide Open

Yes if you use the 6.2 harness. I spent most of the day Saturday crawling around under an Escalade, Denali, 2wd Silverado, and a 4wd Sierra. All the connectors are exactly the same (with the exception of the deletion of the TCU pigtail on the 6.2 harness) on the 07 bodies. You may have an issue adapting the VSS from the 6L80E to the two pin connector on your transfer case.
There is a five pin connector on the very rear of the harness by the transmission tailshaft that plugs into a body harness. I am not sure what its function is but all bodies have this connector.
The first picture below is the connector missing from the 6.2 harness (TCU). The second picture is the “other” connector I mentioned that runs under the electrical center and through the firewall.
I have a local company researching the viability of the 6.2/6L80E swap into my 00 Silverado and a harness company working on making a custom harness to use an E67 ECU (utilizes both CAN and serial data I believe so my gauges will work).
If neither pans out then I will buy a 07 and drop in the new combo.
As for why GM won't offer the 6L80E in 08...my guess is because they suck.

niugnep

No transfer case here....reason I ask for the connector number is that I have some access to pinouts but the manuals are tough to decipher...its all over the place. I'm guessing that big harness is the engine to dash harness connector (X109) and like you said its the same for 4.8/5.3/6.0/6.2.

What do the factory 6.2/6speed dash readouts show? Does it read PRNDM? Seems to me you only have drive and then manual so need some way to manually shift. Mod steering wheel controls? You have better access to real vehicles than me it seems.

Hope you have some luck with the electronics solutions, being first is never easy.

Wide Open

Not sure of the connector #'s...
The main harness that plugs into the electrical center is designated as X3 or (C3 on the pickups). The one that goes through the dash and the one down by the driveshaft I don't know yet.
The 6L80E display is PRNDM1. At this point all I care about is the thing shifts then maybe in the future I will fool around with manual shifting.

XLR8NSS

iTrader: (4)

One other thing is you will lose AFM with the swap into a regular 07 since none of the 6L80E vehicles have this feature. It was posted somewhere that GM was having issues with the AFM/6L80E combo and that is why it isn't in the 1500s yet. I've also heard it was because they just didn't have the production capacity yet for the 6L80E to go into all the trucks.

I think I would give up the AFM for a 6.2L/6L80E/AWD/RCSB setup though.