1996 P38 DSE XYZ Switch fault?

Hello all. Please bare with me. Anyone had problems with gearbox selector switch playing up when warm? About 3 weeks ago towed approx. 2/12 ton trailer for a few miles including a steep incline. Engine got a bit warm needle between norm and red, fans from A/C running as connected by thermoswitch ( no viscous fan) .. After switching off engine at destination and restarting 5 minutes later gear selector position not lighting up nor any gear selected on dash readout.." Gearbox Fault" warning light came on. Car struggled to move in Drive. Low/High not selecting. Next morning all back to normal after overnight cool down. Since then all is well until I drive for half an hour or so ( no trailer ) and she warms up to normal temp but when switching off at destination " Gearbox Fault" lights up and same symptoms appear. When left to cool off all back to normal. Transmission fluid clean and correct level. Cooler not obstructed. So back to my original question. Has anyone come across this before?

You need diag on it to see what the gearbox fault is. If you are towing fit a viscous fan before you damage the engine.

Thanks for reply. Towing a bit of a one off but take your point. I posted a thread on here a while back re: genuine viscous fans on e -bay at a good price and was too slow in ordering one! Getting diagnostics in this area a problem. One so called Land Rover specialist will not touch P38's at any price the other only works on older Discoveries/ series/ Defenders. That leaves main dealer 45 mins away and wants vehicle leaving with them for a plug in diagnostic? I just wondered if anyone else had a similar issue when system warm?

allanw said:

Thanks for reply. Towing a bit of a one off but take your point. I posted a thread on here a while back re: genuine viscous fans on e -bay at a good price and was too slow in ordering one! Getting diagnostics in this area a problem. One so called Land Rover specialist will not touch P38's at any price the other only works on older Discoveries/ series/ Defenders. That leaves main dealer 45 mins away and wants vehicle leaving with them for a plug in diagnostic? I just wondered if anyone else had a similar issue when system warm?

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Not heard of that problem. That is why you need diag. When you know what is causing the gearbox fault you can work from that. The engine ECU and gearbox ECU do talk to each other but can't see that being the problem. XYZ switch tells the gearbox ECU which gear is selected and lights the gear selector gate red indicators but it is the BECM that switches the gear indicator on the message center on. The box maybe going into limp mode for some reason.