 I would suggest you start with OBD2 because OBD2 language is very consistent and easy to understand where manufacturers, Chrysler calls fuel trim one thing, Ford calls fuel trim another, and GM calls it yet a third, a different way also. And you will find that, you know, you are looking for certain things like find coolant temperature in a Ford product. Certain Ford products don't use coolant temperature sensors. They use cylinder head temperature, CHT.