Ditto, how did you guys go about doing this? I assume not with HPT since they are saying you can't just flash the TCM only.....I have a buddy at a GM dealership if that would help me?

 

just call your local junkyards and look for a tcm off a 08-09 2500 express van and just plug n play. i got mine for 50 bucks from a junkyard in houston. doesn't matter if the van is 4.8 or 6.0 they all came with the 80e. make sure its 08-09 because 10+ came with 6 spd trannys.

 

Even if mine is a 07 do you think that matters?

So you install the TCM from the Van, read entire and now the PCM is the same but the TCM has the stock 4L80E stuff in there, sounds "easy"

 

yeah man it'll work. all i did was got the tcm in the mail, plugged it right in (harness repinned of course) and bam speedo works, all gears, lockup, everything. been using it for almost 2 yrs now no issues only the tow haul but that's in the tune. no need for hptuners if you get a van tcm, like i said, just plug n play.

 

Alright, will send a note to my contact at the junkyard and see what I can find

 

cool. good luck on the build

 

JY replied with a whole list of "compatible" TCM's from Pursuit's to to Monte Carlo's and trucks etc. which is a bit odd........ However they list the below, should work right?

│ SILVERADO 2500 PICKU 07 Transmission, new style (smooth Dr skin), 6.0L, (│
│ SIERRA 2500 PICKUP 07 Transmission, new style (smooth Dr skin), 6.0L, (│

Actually, this is more info that they sent:

for the 07 silverado 2500, my options are:
1)Classic Style (creased Dr skin), (LH fan shroud), (6 speed AT, opt MW7)
2)new style (smooth Dr skin), 6.0L, (next to battery)
3)new style (smooth Dr skin), 6.6L, (LH fan shroud)

and for the 07 sierra 2500:
same options as above

looks like option 1 I don’t have available

option 2 I have 4 available, I will give you the specs of mine, perhaps you can cross ref it with the dealership to see if any of them will work for what you need it for?
*ID# 24235340, VIN: 1G4HE57Y76U165649
*ID# 24230461, VIN: 2G1WB58K179366615
*ID# 24243258, VIN: 3GSCL33PX8S718789
*ID# 24249233, VIN: 3GSCL93Z89S517477

And option 3 I don’t have available.

The ones that I do, none of them are out of sierra or silverados, they are all from lucerne, impala, and vue, my system seems convinced that they are the same

 

has to be off a van.

 

is this the only option for running an 80E on an NNBS truck?

 

From my research it seems there's 4 options, (#1 no wiring changes due to harness and option 2/3/4 still need to do the wiring modifications):

1 - Buy a harness like Frost and remove some codes as per their directions (someone might want to confirm this works on the NNBS)
2 - install a TCM from a 08/09 Express/Savana Van with the T42 TCM and 4L80E
3 - bench flash a TCM with a file from a 08/09 Express/Savana Van with the T42 TCM and 4L80E
4 - IF you have connections at a dealer, give them a VIN from a 08/09 Van and ask them to flash only the TCM.