Need help - 07 Avalanche engine/tranny swap to LS2 with 6L80

[eddysal]

Gents,

Need help determining which ECM to change to for my 2007 Avalanche project. The 5.3L and 4L60 have been replaced with 6.0L LS2 with 6L80. Changed engine/trans wiring
harness for the 6L80 (GM part for 09 GMT900). Researching several sites / forums / local tuning shops, the information I have found leads me to believe that I need to replace the existing E38 ECM that came with the vehicle with a ECM that is compatible with the 2012 6L80. Information I have obtained has some ambiguity regarding vehicle VIN and trans VIN and need further guidance as to what will actually work with this engine/tranny combo.

Does the ECM need to be changed to match the original vehicle VIN to be compatible with the 07 Avalanche Body Control Module and Cluster Control Module? What about TCM VIN code clashing with new ECM? Also, would like to get the BCM and CCM talking so the downshift/upshift button works... I have located a 2012 Chevy Tahoe ECM - this Tahoe came with a 6L80. I am not a tuner. Any help would be greatly appreciated.


Thanx,
Eddy

[Taz]

This is DIY conversion question - and doesn't relate to EFILive software use, as you don't have the software - which is the purpose of this Forum. These questions should be posted on DIY sites - like LS1 Tech or something similar.

Without a complete list of your hodge-podge of parts, it is impossible to fully answer your question, but I will point you in the right direction.

In an OEM vehicle, where you require integration with the other modules (i.e. BCM) on the CAN Bus network, you need to use a compatible ECM (E38) OS. In your case you should run a 2007 E38 loaded with a 2007 OS designed to work with an A6 (6L80).

In your case this means changing the TCM (T43) to one compatible with a 2007 TCM OS.

It sounds like you have a 2012 A6 (6L80) - the T43 TCM in that transmission will not work with a 2007 A6 (6L80) OS. These TCMs are very easy to change, and cost between $500 and $1000 from GM - depending on the unit required.