Hoping to see if anyone has a schematic for this machine so I can get to tracking wires. Already went thru the power and grounds with no luck.
Check your message inbox for an electrical schematic. Before you go diving into the electrical system can I suggest that you do some reasearch first. E459 is a quite common problem so if you use that as a search term it should throw up a load of bedtime reading for you. The problem could be anything from a poor ground connection somewhere (be warned there are literally dozens of them, the electrical schematic shows them all) to a break in a wire inside the engine wiring harness. Do the simple stuff first would be the best suggestion. I'll be honest and say that the only way I would suggest to test the load carrying capability of a particular typical 14-18 SWG wire found in one of these machine harnesses would be to first disconnect both ends of said wire, connect one end to machine frame ground and then supply the other end with batt+ via a fused 5A test light. Any wire that will carry 5A without exploding should be able to be classed as good. Don't trust a resistance reading on a multimeter, the wire could literally be hanging by a thread and incapable of passing the required current.
Agree with the bulb test ^^^^, as heavy current will test the real strength of wires. Just out of curiousity, how did you test the powers and grounds. Would be good for you to check out @acolar who posted July25/2021 on a Cat259D. He posted a picture of the Power Block Under the cab that was all green. There was another post of guy who finally after persuasion found a burn't fuse next to the relays hiding under the cab. Better check out these locations very well as he had said it was all good and found he missed one fuse. He had to clean up a lot of stuff. Simon C