immobiliser problam

hi all got a bit of a problem with my newly aquiared td5 discovery.
when I first got the beast the central locking wasn't working so found out the drivers side lock was goosed.i changed the lock and guess what still no joy but it locked and unlocked on the key but as soon as you opened the door the whistles and bell sounded off.it was only when I touched the barrel with the key that the doord locked and unlocked so my question is could it be the rf signel that's bolloxed or something else

To gain access by using the key in the driver's door, you'll need the Emergency Key Access (EKA) code. That might be in the paperwork you received with the vehicle, but you'll probably have to visit you local LR main dealer with proof of ownership, the V5 clutched in your grubby mitt.

The usual things to check first are the fobs,you should have two and then the RF receiver in the roofspace.

The excellent post and attachments by @neilly, found here will give you a load of information about the central locking and immobiliser:-

https://www.landyzone.co.uk/land-rover/handy-buying-alarm-info.311291/

Hi. You need a working fob to not trigger the alarm and immobilise it, without that EKA code is needed

Hallo Sierrafery, i need you for my electric problem of my Discovery II.
I've the auto immobilizer that not work and the control remote that not communicate with receiver. All of this happened when I entered the EKA code for disable the anti theft because the remote system has failed several times in one day. Subsequently for this problem I replaced without success, in order: the RF, the BCU, Fusebox & IDM and finally the ECU. I've buied all from Discovery2parts (Paul) but i don't resolve them. The earth points worly fine. The anti theft and immobilizer work only manually with keys. Perhaps the BCU is in a type of sleeping mode and with my Nanocom i can't a wake up it. Have any idea? Thanks a lot in advance!

How do you know that your key, or keys are not faulty.
What diagnostic equipment have you used.

Hi Roi, my keys have a new battery, the switches work (the red light turn on). My Disco is second-hand and the old owner gave me only one key without a battery (he did not use the remote control for open and close). I inserted a new battery and RF communication started working after a week or so. I buyed another key from ebay and i synchronized it in BCU with Nanocom. After a week it happened what I wrote previously. Auto immobilizer and RF system don't work from two months ago.