Sorry ive not made it clear. The gearbox seems to be functioning correctly at the moment after i reset the driver adaptations and adjusted the xyz sensor but time will tell.

Im now chasing a fault that's causing the gearbox to overheat light to illuminate. The light is on straight away when you start it from cold so it's not hot.
Where is this rave people go on about?
I have tried disconectin the switch but it makes no difference. I have continuity between the two wires and the body so if there is only one switch i must have a short somewhere.

Pound to a penny it will be the auto g/box oil temp switch on the oil cooler as previously said as they aren't the most reliable things. I had to do mine as it had the same light on from cold problem as yours.

Genuine Radiator And Cooling System (2.5l 5 Cyl Turbo Diesel) For Land Rover Discovery 2 1998 - 2004 Classic | Jaguar Land Rover Classic Parts
Link for the oil cooler/switch (item 18) click on the description part for the part no/price. I just ordered an aftermarket switch for under £50.