06 ETC is not compatible with a 04 OS. It will go into reduced power mode. There are two sides to VATS. There is the starter enable which is in the OEM lock cylinder and BCM that enables the starter relay then there is the fuel side that is controlled by the PCM. (starts, runs for a second then dies. You can only disable the fuel part of VATS in the PCM. If you post your bin here you read out of your 06 PCM I can tell you more about what you have and even edit it for you.