You may not have been following this but this has been going on for a few years now.

In case you get into a bit of trouble working on your JD or know someone that is you might want to point them at these articles.
https://motherboard.vice.com/en_us/article/kzp7ny/tractor-hacking-right-to-repair

This is pretty good from folks that really don't understand the economics of agriculture. People in ag have been keeping up with tech pretty well. There really isn't much choice.
https://motherboard.vice.com/en_us/article/pamkqn/watch-tractor-hacking-john-deere-right-to-repair-documentary

There is a mention of a GPS unit in that video. These are used primarily for soil nutrient applications. We used to do several soil samples in a field and then mix them all together, you need about a 5 gallon bucket of samples to mix and then you take a pound or so to get tested. Then you get the recommendation for that field and the intended crop. This is still a good idea but if you check you will find that orbital spectrometry is capable of very, very accurate soil analysis. Physical soil tests are primarily used, on large cropping outfits, to check on the remote soil analysis. By using the maps that are created of your field and feeding that data into your tractor you connect to the equipment to apply the soil amendments and they are then applied at the rates needed for the part of the field you are actually applying the stuff too.

This cuts down on runoff for better water quality protection and saves a lot of money by not over using the stuff that cost a lot of money.

GPS in tractors is not a new thing at all. Been around more than a decade in fairly common use. All new tractors, pretty much since the turn of the century, come with a place to set a laptop in the cab where you can reach it from the seat and use it.

Is the primary reason I am not holding my breath for self driving road vehicles in any large number. Or capable of actually getting somewhere correctly. They have been doing real work on this for a long time in tractors. You really have all the controls for equipment set up to run pretty well unattended. But you still need someone in the seat to drive the stuff. This is extremely boring driving. Up and down a field. Or around and around in a field. Something that sounds pretty simple to control really. You have damned good maps available for most fields. The turns in the "head lands" are pretty standard U turns. Just need to turn and then follow the GPS. No traffic problems. Just cover all the ground in stripes. Isn't ready for use. Been following the research on that since 03 pretty closely.

That research, rarely if ever mentioned, is the basis for self driving cars. Not ready yet at all. May be in another 50 or 10 years.

The cameras that vehicles use to navigate around hazards are getting pretty good but depending on those rather than GPS for navigation is pretty tricky in itself. And tractors don't need to do that sort of navigation. They just need to accurately, more accurately than the average, say, 13 year old can do in running up and down a field or around and around a field working either in to the center or out from the center.

I suspect you could train an Orangutan to do that job. I have known a whole lot of pretty seriously "impaired" people that are very good at that sort of thing. But they really haven't gotten a computer to do that job reliably.

I can see driving aids. I can see "linking" several trucks together electronically to follow a lead truck being driven by a person. I really can't see, except in very controlled and well marked areas, vehicles that can really do the job without being real hazards. Will come eventually but definitely not tomorrow.

And it may take some dumb farmer to figure it out.