Greetings!

Is the 1994 Ranger fully compliant or partially compliant with the OBD II protocol? I've seen various information stating that 1994 might have been a transition year for OBD II and therefore some or all of the data may not be accessible through OBD II. I think model year 1996 was the year that all cars were required to use OBD II, but 1994 and 1995 are a little fuzzy.

Is OBD I the precursor to OBD II? And would a 1994 Ranger use OBD I codes?

Finally, will an OBD II scanner read OBD I codes?

Thanks!