Probably a under bonnet fuse box problem.

Check the maxi fuses for brownish contacts & clean with emery cloth or wirewool.

 

Thanks Rick-the-Pick, have visually checked all fuses and will be checking the fuses again and the wiring connections between BECM and ECU.

Now other strange things are happening since to the Rangie, ie; central locking working on its own, alarm sounding for no reason and all this only seems to happen when parked on my driveway. And now I remember even my mates Range Rover central locking operated on its own when parked on my drive. Also the wife has chipped in and said "I wonder if this has any thing to do with our doorbell keep going off on its own?" I live in a built up area and also a few years ago they have installed a large ariel mast less than half a mile away.

After speaking to someone who works on Landrovers they have said that the Rangie might be receiving stray signals causing it to do weird things. He has advised that I should dissconnect the RF receiver and test the vechicle each day for a week. The new battery is fine and not loosing charge. If this is the case will I need a new RF receiver? or can I change the vehicle to european spec in the diagnostic software so that it operates on a different frequency?

 

I was going to say "contact rick-the-pick"!

I believe the RF receiver can be left unplugged, you'll just have VERY limited range on the key-fob remote (which I don't think is a bad thing).

 

Thanks shupack, dont mind going back to the old fashion way of just using the key for entry and starting due to the weird things going on. Its still sat on the drive immobilised as I have not touched it yet and every few hours it unlocks itself and relocks and other times it beeps twice and the computer says "interior lights on" then "interior lights off" with no doors opened or interior lights on :? battery still ok with 12.4 volts.
I think all electrical appliances within 1mile of my Rangie are trying to communicate with it :twisted:

Will be attaching a diagnostics machine to it on saturday to reprogram the immobiliser code to get it started then will disconnect the rf receiver and see what happens over the next few days ray:

 

Just a quick update ...

Plugged in diagnostics machine and re-entered immobiliser code to ECU and engine started
Unplugged RF receiver and left on the driveway. All quiet for four days with no battery drain
Plugged in new RF receiver YWY500170 (£200 :shock: ) and all seems quiet with everything working correctly
Only been one day but keeping fingers crossed and remote by bedside just incase of any more 4am alarm calls :roll:

 

Hi, Dengiboy,
I have a year 2000 p38 Vogue fitted with a 2.8 International diesel, I had the same problem last week. Took my wife shopping,left car in carpark,locked it ,all ok when I tried to open the door with the key fob,no, opened it with the key,would not start,message centre said, enter code. What, I havnt got the code here, its at home.car park charges going up by the minute,panic. caught the bus home,got the book,back to car,entered the code,engine started,returned home,stopped engine,same thing happened again,re-entered code,then had a brainwave,I held the keyfob against the rear side window, pressed unlock and engine started ok,one week later its still ok,so far so good. The morrel of this story is, always remember the code,you never know when you may need it,its better to have it and not need it,then need it and not have it.after all, its a p38, and anything can, and will happen.
Briang.