The reason why it doesn't lite up on the cars without it is the bulb is not included in those models... If you remove the instrument cluster you'll see that there is no bulb in that socket.. No bulb- No lite.. Simple.. And yes, I believe that the ABS module has to be programmed to turn the TC on.. It's not just a switch and go or it would be on all the time.. Not just when adding the switch.
Dom
