There is something wrong with the tractor. The water-in-fuel sensor, a small device embedded in the John Deere machine that monitors the integrity of its diesel engine, is disconnected. And I’ve got to fix it. I’m not a mechanic or a farmer. I’m poking at a laptop at John Deere’s corporate office in Santa Clara, California. There’s a cable connecting the computer to a 5130ML tractor sitting on the grass nearby. A bright red notification sits on the screen, telling me something is wrong. I type in a question and the software pulls up instructions and a few images from the user manual that matches the serial number of the machine. Photograph: Boone Ashworth I wander over to the tractor and find the parts modeled on the screen. I spot the sensor, with two very obvious dangling wires that need to be connected together. I press them together, hear a little click, then step away and look back at the screen. The notification has cleared. Everything seems to be fine.…