G'day mate and welcome to TBN from Downunder.
What I would do is to call/visit your JD Dealership, or any JD Dealership, and talk to their Parts/Service department. They will be able to explain the the Code and provide a schematic to locate the solenoid... for free. If they're too far away, they'll email the schematic.
I know that my Dealership would do this. They'd also provide the advice of a mechanic.
Enjoy the site.