Sooo... what's the configuration breakdown by year for the vans?
Sounds like there are about 4 different configurations of Duramax van, in terms of the network system used:
2006 LLY/4L85E - GMT800 based?
2007 LMM/4L85E - Bastard child?
2008-2009 LMM/4L85E - GMT900 based?
2010-2015 LMM?/6L90E - GMT900 based?
I'm asking this question with an eye toward the transmission segment swap mentioned above... the possibilities and method are going to be different based on the GMLAN version used in the vehicle.
Well there is more to that.
1) Built between 08/2005-12/31/2006 are LLY vans. This includes 06 and some of the 07 model years. 8th of VIN = 2.
2) Built between 1/1/2007-08/2007 are 2007 model year LMM vans. All LMM vans have DPF. You can tell those by the 8th digit of VIN = 6. Those vans also have the old style dash and IPC, and the Diesel Text fuel above the odometer (LLY vans did not). See pic. Those still use Class 2 comms for IPC/BCM/ABS stuff.
3) Between 08/2007 - 08/2009 are your regular model years 2008 and 2009 LMM/4L85e vans. From this point on, all are GMLAN, no more Class 2.
4) 08/2009 - 12/31/2009 is the only short period of time where you could get the 6L90e behind the LMM. Because of short run, those are hard to find. Those vans would be calendar year 2010, 10th of VIN = A, 8th of VIN = 6. Or look at the driver door sticker for xx/09 production date. In other words, 6 speed without the DEF. They were still rated at 460lbft, unfortunately. Although perhaps can be tuned to go 525 to match the rated 6L90 torque limit.
5) 01/01/2010 and until end of production in the middle of 2016 are LGH/6L90e vans. 8th of VIN = L.