With all the great information found here, i've been able to take an E38 ECM from an equinox at the wreckers and flash it using GM SPS to a 2007 C6 Corvette M6 OS. This has netted me all the manual features of the M6 OS to go with my TR6060/LC9 swap into an E46.

Engine has been run to confirm the harness and pinouts are all good, but i'm currently working on the harness and was working on planning ahead for cruise control. I understand the chassis i've chosen has its inherent challenges with CAN-bus, but was hoping in the interim, I could get the cruise working using some aftermarket buttons/switches and a factory BCM.

So far i've found the GM wiring for the BCM and understand the resistors required to simulate the various cruise buttons on the steering wheel, but where i'm coming up short on information is interfacing the BCM/ECM. Wiring side of things is clear to me, just the communication via CAN is unclear on what's required to ensure they communicate.

From what i've read, the BCM needs to be from the same VIN and model vehicle was the OS flashed into the ECM. Seeing as I only need 20% of the features offered by the BCM, is there any chance that the ECM would communicate with a BCM from a different vehicle type/VIN ? Corvette BCM's are $$$ and even moreso to try and find the pigtails/connectors to suit. I've managed to pull a BCM from a 2007 1500 truck with all the pigtails ready to splice for $20.

If someone can confirm they won't communicate, my next avenue will be to use the GM SPS subscripton i already have from the ECM flash to try and flash the corvette BCM/VIN into this truck BCM and see what happens. Subscription is already paid for, and if I brick the BCM, i'm only out $20 which wasn't going to be useful to me anyway.

Curious if anyone has any first hand experience here to save me wasting time on something that is known not to work.