Originally Posted by
bloc
Mostly, yes. VATS delete was a non-issue.
I did not copy DLIS and simply gave the BCM ground, constant +12v, +12v accessory, and all of the GMLAN circuits as in the EWD. I now have smart charging, tap shifting (with a home-made copy of the truck switch, note that this needs a truck transmission tune), reverse lights, and cruise, all through the BCM. The only real glitch is that without a driver's door module installed to communicate with the BCM the "retained accessory power" timer never gets reset when you open the door. What this means for me is that after shutting off the ignition I must wait ten minutes before cranking again or I won't have cruise control. Tap shifting and smart charging don't have this issue, for some reason.
I'm reasonably confident copying the DLIS circuitry would avoid the 10-minute issue with cruise, even without a door module.. however it's not worth the work to try and copy DLIS.. or at least the ten minute timer isn't enough of a problem to justify it for me. White Audio Media can probably program a BCM to ditch the timer, not sure what they'd charge.
Also note that if my understanding of all of this is correct, you'll need a BCM that is coded with the same VIN as the engine/transmission. So grab yours with the swap stuff.. otherwise I don't think it's worth the work.