Today i had this problem:

Engine System Failure!

Cool. Switched off the engine, waited 3 minutes and it works! what could this be? ok, at 120 km/h i switched the gearknob to N (have to save diesel at this hard time ) perhaps this made this problem? RRS TDV8 Modelyear 2009 with some modifications.

"coasting" at 70mph! I think you may have confused numerous ECU's into submission / total confusion  2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Mate, is it a V6 or V8? Do you have DPF?
If so, I bet it is some f sensor...

Maybe you confused the EGR (Exhaust Gas Recycling) unit. Most engine failure lights are caused by the EGR "sensing" a problem. If the light has cleared it should be ok. RRS TDv8 HSE Rimini
Disco 4 TDv6 HSE Ipanema
Defender 90, 200tdi CSW

I have the V8

I drive often with N.. nothing happens till now. . I also have the dpf. i thing some sensors stopped working or anything else. after that i had no problems.

last week my pdc didnt worked. i should go next week to LR, they will repair it. yesterday, it worked again.. landrover said, its "damaged". I think its an loose connection RRS TDV8 Modelyear 2009 with some modifications.

F sensors

Stealer mate...
ECU will have the fault stored and hence easy job to solve...