John Deere is the company engaged in legal battles with their customers. Customers want access to tractor data for their own diagnosis and repair. JD claims that info is proprietary and will not make it available.
The article in the link below starts with:
Farmers Fight John Deere Over Who Gets to Fix an $800,000 Tractor
John Deere
Dave
On another forum I mentioned that my farmer friend down the road had a couple million in JD rolling stock and most all of it is no more than 2 years old and all computer driven. He has to use JD filters and JD lubricants, everything has to be JD. Reason being, even the filters have sensors in them that 'tell' the computer when to change the oils and the computers talk to JD via the dealer. If they get an error code or have an issue, the local JD dealer won't tell them how to address it, they have to do a service call and hook up to the on board computer and only a JD certified technician can do that.
Much like Kubota's proprietary interface on the newer T4 final units, only a Kubota dealer can access the 'brain box'. Too bad they (tractor builders) didn't standardize the ports like automotive did where no matter what brand you buy, the OBD port is the same for all. Like Deere, Kubota won't sell you a code reader but you can buy a code reader / scan tool for any automotive application. In fact the code reader I own will tell you which component need to be replaced so you aren't throwing parts (and money) at an issue and not knowing WHAT i9 causing it.
I certainly hope the folks suing Deere win in the end but JD has a ton of money to fight it.
Been down there to watch before.
You talk about emissions controls on the newer Kubota's, JD really has some hardware (and software). The downlink on the tractors works through the JD GPS tracking system and it's all proprietary stuff.