Back on the gearbox merry-go-round...
 

So after spending $2k to get the Kj's trans solonoid block replaced two weeks ago the issue is back again.... Same symptoms as last time. I don't know what code it threw this time as we were outside of Lithgow with a 4hr drive home so I just pulled the battery +ve lead to reset the computer.

Luckily the issue didn't come up the rest of the way home but I'm in a bad place with the KJ at the moment. Evil thoughts of trading it for a Prado or Pajero are circulating around my head.... :shock:

I don't know what transmission is in the KJ uses but I'll share some experience on a WJ grandie that suffered random transmission fault that I had to sort out on the daughters car.

It suffered random events of going into limp home mode, locked in second gear and the MIL lamp illuminated, fortunately for the daughter it would usually reset if she turned the car off and restarted it.
If I did a scan and found it was always a speed sensor fault and after replacing it twice the second time with a genuine mopar sensor the fault still came back, just less frequently.

After further research I came to suspect the sensor electrical plug, although it wasn't damaged but I felt its sockets may have been loose on the sensors pins and causing intermittent connection occasionally.

I rewired the plug with new sockets and the problem was finally corrected that was about 2 years and around 50,000kms ago. Now you may be not getting a speed sensor problem but you may have a poor connection inside one of the electrical connectors to the solenoids in the transmission.

The original fault I was getting was a p1776 - solenoid stuck in LR, so unfortunately nothing to do with the speed sensor. Could still be a loose connectgion in the wiring somewhere, just waiting to hear back from the mechanic who did the solenoid to see what they'll do next.

After spending $2k on what they said was the problem, I'll be pretty firm about not paying for more diagnostics.

I am not suggesting you have a speed sensor fault but I was using the example too demonstrate that you likely have a connection fault.

I hope that's all it is. Will certainly be getting the transmission shop to test all connections from the box, back to the TCM and ECU to see if it's in the wiring.