My used 2013 Grand Caravan has the basic version of the TPMS. I've verified that through a dealer checking the VIN. When I bought it used, it didn't come with sensors in the tires and the TPMS light has never been lit, except when I turn the vehicle on and all the hazard lights come to display they function. I'm trying to figure out why the TPMS isn't going off. I don't want to buy new sensors, or start replacing parts at random, and then find it was something either very simple, or completely unfixable.

I'm importing my vehicle from Canada to the USA and it needs to have a functional OEM TPMS to do that. An aftermarket system will not help me out in this situation.

Any thoughts welcome.