Yes, having the ability to read and interpret codes is a big step forward but it's not going to magically transform a hack into an expert.
Exactly. And codes do not give a magic bullet to tell what part has failed. With the code and with knowledge of the systems involved, one can design a troubleshooting strategy that arrives at a proper solution. Too many think the scan data is the end all. The "Magic Diagnostic Genie" told me to replace the framise widget but it didn't fix the problem. No, the diagnostic tool told there was an issue with that part but never told what that issue might be.
We've all seen dealer mechanics who just throw parts at a piece of equipment, let alone owners trying to DIY repair.
Yep. Wanna know why? They are taught to "gitterdun" fast. Don't worry if you have to throw more parts at it. On customer pay, we make more money. On warranty, the factory pays. Just "gitterdun".
Often the dealer techs are right out of school, are handed a diagnostic tool and told to follow the instructions on the tool. When the problem lies outside the "engineer designed fault tree", the technician is lost because no one is taking the time to teach the systems.
Todays machines require skills in computers, electronics, mechanics, and hydraulics. It is a lot to ask of a technician. 18 to 24 months of training is suppose to equip a technician to work on these machines? I think not.
Techs who do learn and are the best then get screwed by flat rate pay. The talented techs are given the challenging jobs that take more time than the book says it should take. Their pay is defined by how quicky they can get the job done. The simple jobs which can be completed in book time, go to the lower level techs. The talented tech sees their paycheck shrinking while the less talented tech is paid more doing oil changes. The next step is the talented tech wants out and leaves the dealer for a place that appreciates what they can do.
I talk regularly to automotive tech trainers and they really hate the system in which the young men and women in the auto repair trade must work. There are many trying to change it.
I don't have experience with the Ag dealer technicians. If I had to guess, it is similar for them.
All this leads us back to the "Right to Repair" and the question of who can actually repair these machines. My experience tells me that those who choose to learn will be able to be successful if they have access to the tools and materials. If that were not true, I would not be working for a company that has provided tools and information for 21 years, allowing car owners to repair and to modify their cars. "Right to Repair" should provide the owners of these machines with tools and information by which they can learn and can be successful fixing. And yes, users will make mistakes and break things. Part of the learning process is learning what does not work as well as what does work.