John Deere remote SCV control

[m_elias]

Most of the information I have comes from @ChrisC on the OpenGrade thread.

He first mentions the electronic control method here.

Grade control

I originally was going to look into can, but there is a simpler way… all deere, cnh, and cat tractors made in the last 15 years come with a scraper interface… basically you plug and play. DAC 8000 Wired - Manuals Not sure of the wiring for cnh or cat but here is the configuration of deere [IMG_20211024_123559] It is a 5v analog input that doesn’t like extremes. So 0-2.5v controls one direction and 2.5-5 controls another… CNH and JD have a dead band from ~2.25 – 2.75 volts, this varies some …

Then at post 496 there’s another bunch of details.

Grade control

It’s a deutsch type connector [IMG_20211226_163440] Yes plug it in with the tractor off, if you mess up it will throw a code that has to be deleted before it will work again. The scv acts like normal except when detented full forward. When detented it goes to automatic, everything else acts like a regular scv.

It sounds like the JD expects voltages of 0.5 - 2.25 for one direction and 2.75- 4.5 for the other direction. There’s some deadband in the middle (2.25 - 2.75). So basically, at 2.5V there’s no oil flow, and as the voltage goes further from that 2.5V (to either 0.5 or 4.5) there’s more oil flow to the remote ports.

If you’re experimenting with this, make sure to leave provision for disconnecting and restarting the tractor to clear errors. Only connect/disconnect with the tractor turned off.