From what i have read on the GM site they are gonna start making the Dealers send or take pictures of the ECM when Hooked up to the truck to show No mods have been added so it will not be the Dealers Call for long,If that goes into effect...
It was said ,this will have to be done before Warranty work will be granted...
They (GM dealers) already do that. The 2007 and newer Dmax ECM records the CVN's (basically like a computer software CRC within the ECM) of the past 10 flashes. So if you flash something thats "not-GM" it will show up in the ECM's reflash history. The tech then takes a picture of the Tech 2's (the GM dealer diagnostic scan tool) screen that shows the CVN list and forwards that to GM before any major warranty work is performed/authorized.
The EFILive guys have stated that technically its possible to fake the CVN's but its highly unlikely they will release the capability to everyone because that raises a lot of legal/ethical issues....and IMO they are exactly right. You play you pay.
Why should GM (or ford, or dodge) pay for a new motor because you blew a hole in your #6 piston after towing up a long hill with a huge tune?
To think otherwise and/or try to get something covered under warranty that is YOUR fault is stupid and slimy.