Ok just to add my two cents also. The vats system is fairly simple to relearn no matter what module you replace and equally as easy if you replace every module. I find it difficult to believe that dealership would not do a complete relearn on the security using the techII. If in fact you were in a security fault situation the security light in the ipc will be flashing, and yes you will have a PCM DTC which is described as VTD fuel disable. Granted Snap-On may not have the ability to see all of the factory DTC's, I really can't say I have zero experience with there scan tools. I also want to remind everyone that there isn't actually a chip in the key on these systems, as stated above the ignition switch is the component for providing the IPC with the security signal although this is not application specific it is a generated signal based on time of pulse as the ignition is cycled from off to on. If you were to perform the security relearn properly the signal sent will be the only signal recognised from then on. I hope this may clear up some confusion on the VATS which is Vehicle Anti-theft System and has seen many different methods of providing vehicle theft protection including keys with chips which were very problematic and not very secure.
Shane
