Hi Redrange.
Correct!!!- a fob with a different lockset code is as much use as a chocolate teapot other than as a means of holding the key. As you know, the keyfob is excited when it is put into the ignition switch to send it's "Code" to the alarm ECU via the BECM. If the code does not match that stored in the BECM then you cannot start the car.LR Engineers really went to Town on security on the P38. It is adviseable to have the lockset code as it would be required if ever the BECM had to be changed. The only safe way of buying replacement keys would be to buy all the locks from a vehicle, complete with the BECM and to be 100% safe, have the lockset code as well. Your LR dealer where you purchased your key from should have, or be able to get the 14 digit lockset code for you, proof of ownership may be requested. Alternatively, the lockset code may be retrieved from an UNLOCKED BECM by Test Book. If using Rovacom, as I do, the lockset code has to be converted by them to their own format. Unfortunately, gullible fools will still buy these fobs second hand and pay half price thinking they have a bargain, only to find it does not work, then put it back on the web for the next sucker that comes along.