I make this post because it looks like that there are still many P38 suffering from battery drain.
I consider that mod very important since battery drain can cause odd issues on that vehicle :
-alarmed BECM (need to dismantle it and have it unlock)
-burnt door locks
-EKA mode not responding
All the information is here :http://www.rangerovers.net/repairdet.../batdrain.html
Stock receiver do not work with new wireless environment : Wifi, Bluetooth, Infrared, Home-Link, Alarms, Key-Less Entry from other cars, Remote from other P38s....
Consequence is BECM do not go asleep and battery drain in those conditions is 500mA instead of 50-100 mA.
That explains that a non asleep BECM can drain a battery in 2 to 5 days instead of 3 weeks.
All years of P38 may have the problem since last P38 is 2002 and Updated RF receiver was released in 2005.
How to recognize genuine updated RF Receiver (or how not to be screwed)?
First, find the **** box.
It's here on RHD in the trunk near rear RHD seatbelt and very closed to the push button to fold back seat
Watch this photos found here : http://www.mez.co.uk/p38.html
They all look the same and there's not any information or PN outside.
The only way to know what you really have is to dismantle it. The lid is clipsed
You do not need any reprogrammation for this reliability mod.