Comment by bri3d

I agree that J2534 is sketchy. The standard isn't very good to start with, there's usually no matrix (ie x systems * y devices) conformance testing but instead just a brief QA step done at some compliance stage in a release process, and most manufacturers don't really want to support it (preferring their in-house dongles). So, a lot of dealer tools do non-standard stuff and a "conforming" J2534 cable doesn't actually work.

Many subscriptions are painful, yes - VW brands / ODIS for example are awful to try to get as an individual and annoying as an independent shop; I'm sure the fraction of independent shops who pirate it are quite high. It's funny you mention Ford though, as they are incredibly easy to buy from in my experience, although the login/licensing backend is frequently broken.

However, there's a good cottage industry of companies reverse engineering the compatibility issues back out, and for better or worse these companies are cloned almost immediately too. I recently did key programming on a newer Ford (where Forscan can't) using a $125 VXDiag cable which I could have bought cloned for $30 and a short-term FDRS subscription that cost $50.