Genie GTH 1048 Telehandler shutting down

Hi Yall,
I am a new member but have a machine that is giving me some trouble. I have a 2006 Genie 1048 telehandler that is shutting down. I just bought this machine a little over a month ago from a private dealer who sells stuff on the side. Engine is a John Deere 4045. I will start it up first thing in the morning, and it will run for about 8-10 minutes fine, then will shut off like you turned the key off. After that it will only run a minute each time before shutting down. If you leave the key off for about 20 seconds it will start right back up. One thing that I've noticed is that the transmission pressure gauge is pegged, past the numbers, and once that starts to relax is when it will let you start back up. Maybe a coincidence. I had a mechanic tell me that all genie lifts with the trans gauge runs pegged out so im not sure what to think.
We replaced the key switch, fuel pump, fuel filters, blew through the fuel lines, hydraulic filter. I pressure washed the radiator and engine. I replaced the trans oil and filter, and it was pretty murky and low, and I ran it over a half hour fine without shutting down.thought the problem was fixed until later in the day it started shutting down every minute or so. I had a guy read the computer, all it said was code 000970.31, Auxiliary engine shutdown switch active. Looking up the code number reads Non engine fault. Check other Shutdown devices. From his reader everything looked fine, Engine oil was 55psi, water temp was 142. It seems like once the machine warms up is when it starts shutting down.
I am going to replace the trans oil and filer again just to be sure its clean, and am going to replace engine oil and filer.
Anyone had any similar issues? Any help would be much appreciated.
Thanks!

This thread has a little info.
https://www.heavyequipmentforums.com/threads/2006-genie-gth-1048.78500/
It seems something is commanding the engine computer to shutdown. Perhaps some fluid level, pressure, or temperature sensor.
Did you download service manual from genies site?

Welcome to HEF Signature!

If you have someone from the Deere dealer temporarily turn off the external engine shut down and your problem goes away then it is definitely on the machine side. If it doesn't then it is an engine wiring/ECU issue.

Engine serial number would also help when posting.

Hi,
Thank you for the replies. So I have the engine family number, which I'm hoping is the serial. 6JDXL06.8082 And Engine model is 4045TF275B,C. We have checked all fluids, sensors and switches that we could find and nothing has turned up. We have gone over a couple of the service manuals, but they don't really tell you much. The wiring harness has been messed with before, so I'm guessing that this machine had this issue before. Is there a mechanical switch that tells the machine to turn off? I will probably need to get someone from Deere to read and check the ecu, I'm not sure what else to try besides replacing the harness or ecu.
Thanks!

The engine serial number is on the side of the block behind the final fuel filter. It will begin with either PE or CD.

The external shutdown feature of the ECU when turned on is usually either connected to a switch from the OEM (in this case Genie) or there is a connection to a Genie controller that supplies the signal for that shutdown. The shutdown feature can be set to shutdown with either a voltage signal or a lack of voltage signal. If you have a Deere tech come out have him disable the external shutdown and then test your machine like I mentioned above.

Check your fuse/ circuit board card next to drivers seat. Have replaced tons of them for this same reason. Intermittent run and stops, fuel pumps shutting of and so on. They are know for getting wet and corroding, broken solder joints etc. they work, get hot , loose contact, rattle. I had a 10k with a Deere motor in it that would loose the fuel pump sometimes at 2-3 minutes sometimes it would run for 30. It was the board. It’s easy to get to and worth checking

Thanks guys for the replies. I haven't had a chance to work on it or look at much yet but I'll get the engine serial at some point.
Txhayseed, you mean the fuse panel under the steering wheel? And what do you mean by card, the whole fuse panel that all the fuses plug into? I'll make sure to check it out when I have time. We are using the machine every day, it's just a royal pain to have to start it all the time. Thanks for the help