hi guys
anyone come across this , on my 2004 v8 petrol i am getting trans fail safe come on screen straight away on start up sometimes or maybe 30 sec ,1 min or 5 min
also when i get this come on screen i have limited drive feels like i am pulling away in top gear , will go away if i switch off on and again but comes back quite often
seems odd cant be gearbox oil over temp because it happens so soon ,

i did have trans fail safe a few years ago but that was 30-40 mins after- and i changed the radiator oil cooler and fliud and the fault went away

nothing comes up under diagnostics also fitted a new battery 3 weeks ago as old one was failing but fault is still there , any ideas  1990 3.5 v8 defender
2000 4.6 v8 30th anniversary prins lpg
2004 4.4 v8 vogue prins lpg
2011 4.4 TDV8 Vogue
faultmate extreme
rsw allcoms
Autel 906BT
Gap iiD tool

update
looks very much like the fault was the inhibitor switch on the gearbox thanks to Rrphil

removed it drilled out the rivets cleaned the contacts and tightened the spring contacts then a little silicone grease for lubrication
i then cut a m5 thread in the case so i was able to join the 2 halves together with an m5 machine screw
refitted to vehicle and up untill now no faults so hopefully a job well done 1990 3.5 v8 defender
2000 4.6 v8 30th anniversary prins lpg
2004 4.4 v8 vogue prins lpg
2011 4.4 TDV8 Vogue
faultmate extreme
rsw allcoms
Autel 906BT
Gap iiD tool