Gday Andy, I used to have a Kv6 Freeelander until late2020 with the Jatco JF506E gearbox, and had changed the fluid myself without connecting scan tools via OBD.
I had a scan tool but the best it could do was coolant temp not auto trans fluid temps.
The kv6 is a large engine and would reach 105 degrees C as your stationary thus no air flow passing through the radiator as your carrying out this procedure. So long as the cooling fans come on at 105, I wouldn’t worry about it, as that’s what the system is designed to do to keep the engine cool. Once the coolant fans come on the coolant temp would fall.
That discrepancy is possible as coolant temps would be subject to higher temps due to needing to cool the large kv6 engine esp with nil air flow through the radiator.
The way I did it was, I took the kv6 for about a 15 min drive and brought it back and shut the engine off. I had a special temperature measuring device with a skinny cable about 2m in length with a tiny sensor at the end of it - I simply placed the skinny wire with sensor in through the auto gearbox fluid pan filler hole and as far down as it can go - it will reach the fluid and there’s your temperature. Then when it’s between 35 and 45 degrees C, turn on your engine and measure it again and if the correct temp is confirmed then go from there follow the rest of the procedure, the risk is that the skinny cable could get trapped in there, but if you carefully wriggle it you’ll be able to get it out.
Another method I used was getting a laser type temperature measure gun and simply undoing the same auto trans pan fluid filler cap, and pointing the laser through there which will come back with a reading, just ensure you strike the fluid with the laser.
And a 3rd method was undoing the level check bolt and once the fluid escapes, measure that with your laser thermometer and there’s your temperature.
I used all 3 methods at different times without issue.
