then most probably Eu3 confirmed if the airbox sensor has 4 wires

HI. Remove fuse F2 from engine bay and see how it runs that way and report... also is it Eu2 or Eu3 engine?

And did you rule out the IDM and BCU both without success like the OP?... if not do those first as it was already explained in this thread

What happenned when you clicked on superlock off with nanocom outputs?

The BCU doesnt store fault codes , check the user guides https://www.nanocom-diagnostics.com/downloads

As you have nanocom you should try with another known good unlocked BCU if the IDM was ruled out

You should have use the unlock command before disabling things cos if it was locked with enabled superlock you should unlock it the same. Let superlock enabled when you unlock cos if you disabled it before trying to unlock it's possible that the superlock motor doesnt work then. If after that...

Use a lubricant spray which has a flexible nozzle , something like THIS , see if you can reach it better through the under dash compartment where the fusebox is

As i said you have to record the "inputs fuelling" on card during a drive not fault codes

Fusebox is in the compartment under the steering wheel, ign pos 2(as to bring on the warning lights)

If a CDL is fitted with the proper linkage you must push the lever to the left to lock the diff no matter if it's in high or low, see this video from 2.20

In most cases, OEM means nothing these days if the brand is not clearely mentioned, it's just a marketing scam, the only reliabe suffix is LR for the genuines and those parts are coming in the LR box

I didnt know that there are so many Discoverys stolen

IMO a D5 should be safe enough with it's factory settings as long as the owner takes care of it's keys to not be lost no need for add-ons... that's quite valid for any Discovery with factory fitted alarm even the early ones

Most probably, they are supposed to be renewed every 105K miles or 7 years according to the maintainance check sheet

Nanocom is from a different league, it can do more complex programming with the BCU than Foxwell or Icarsoft and these are not reliable at all when it comes to Td5 engine management(i learned that the hard way), they are usefull for the other systems, OK with ABS but with less functions.

Yes, there is a RF test in BCU - Utility

Hi. Replace the interior fusebox with 100% good one removed from a facelift, disconnect the battery before the swap then after reconnection turn ignition on(not crank) and let it so 5 minutes.

AA...ha... you should have said that from the beginning, that's very relevant cos if the fob does not unlock and the door's key switch doesnt work the system is not remobilised by anything as it's still in locked condition , do you have only one fob or two and none of them is working?

AAMOF Hawkeye works quite well with the '97 V8 D1 as it is, the gist is that no diagnostic tool would work as long as the vehicle is immobilised which is the case here so the only chance i see is to replace the alarm ECU, should be programmable with Hawkeye as long as the replacement unit was...