the issue is not that this information is undocumented, it's that an "authorized service center" gets information that an "owner" does not. Also cars are not "small open source utilities" with undocumented arguments; do you think that an auto manufacturer has hidden, untested diagnostics that only the dealer uses?

>> don’t think there should be any requirement that they are forced to do additional work

At one time seatbelts, airbags, emission controls, etc were all viewed in this category. Now we have regulations enforcing aspects of all of these. Why would diagnostics be different?