John deere backhoe 315sg, error code F450 comes up. Hitachi said engine temp sensor, replaced but error code still comes up

This may help: How to Clear Codes On A John Deere Skid Steer ' Pap? Machinery (papemachinery.com)

John Deere 310SL Backhoe Loader Diagnostic & Test Service Manual (TM13297X19) ' A++ Repair Manual Store (aplusmanual.com)

Hopefully this will help you some what,,

https://diagramweb.net/john-deere-310-g-ecu-wiring-diagram.html

Question edited for clarity.

We are FIXYA dot com. We don't sell ANYTHING! you posted to Computers, not to the John Deere Category, but we are not John Deere and we still don't sell anything. Fixya only supplies information.

Here are links to sellers of parts

https://www.google.com/search?q=John+Deere+310D+Loader+Backhoe+replacement+fuse+box&

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https://pdfgoal.com/downloads/John%20Deere%20Engine%20Fault%20Codes%20Spn%20Fmi%20File%20Type%20Pdf -------https://www.heavyequipmentforums.com/threads/john-deere-310sg-code-problem.40049/ ---------------https://www.justanswer.com/heavy-equipment/2vsmv-hello-getting-fault-code-f495-john-deere-backhoe.html -----------https://www.heavyequipmentforums.com/threads/trouble-codes-jd-h-series-dozers.6308/

https://www.heavyequipmentforums.com/threads/john-deere-310sg-code-problem.40049/
Here is a forum that might help you.

What is the hydraulic fluid level? It sounds like it might be low.

Thermostat gasket

You just go to the link I attached I'm sure you will get the solution of your problem.
John Deere 310J Backhoe

f-428 means the foot throttle pedal sensor is not calbrated
the software that's in the computer , this makes sense since u replaced the computer recently , to fix this its gonna require the JD tuning tool interface and software 4 it

I suspect the park brakes issue is sort of coming from a similar conflict in sensors on the transaxle or something

gone is the days that a new computer would self adjust its self when 1st installed , in fact if you read your owners book JD requires a yearly software update now

Check and clean all the ground wires. Not just tight but Electrical clean grounds are very important on these models.