Sinc key with imobulizer - 2002 Land Rover Range Rover

Replace the latch. the lock can stay with the car so you don't have to get another key to open it. Also since yours did click, the new one should unlock the trunk. Open the trunk, look at where the latch is. A couple of nuts/bolts a plug and it is changed out.

How long since you last started? Has the copy worked before?
How did you "have the key made". Did a Locksmith make it?

Did it work after he made it? If so Id go back to the locksmith
if the key is the problem. If it's been a while since you started with the replacement key, I'd check the battery.

sometimes disconnecting the battery works

replace the UCH.. the computer of your car..

Immobilisers have been mandatory in all new cars sold in Germany since 1 January 1998, in the United Kingdom since 1 October 1998, in Finland since 1998, in Australia since 2001 and in Canada since 2007. Early models used a static code in the ignition key (or key fob) which was recognised by an RFID loop around the lock barrel and checked against the vehicle's Engine Control Unit (ECU) for a match. If the code is unrecognised, the ECU will not allow fuel to flow and ignition to take place. Later models use rolling codes or advanced cryptography to defeat copying of the code from the key or ECU. You do not say where you live. So have to be a bit generic. Hope this helps.

how many keys do you have? normally it's two keys, are they both do the same?

Hi. Check your ignition key assembly since it is not responding when you turn the key to start position. Check your idling since car turn off while on idle. You might need to adjust the idling.

If the battery is dead or so weak it won't be able to run the circuit inside the key. When the key is plugged in the start, it won't emit the signal to be recognized, the engine will not start.
1- There are 2 lithium batteries in the remote key to be replaced.
2- Is it possible that you pick up the remote key from another Mercedes car in the house since they are all look like.
3- Since you can open the door manually it means the key is correct. However, kids in the house and swap keys from FOB from its original ones.
4- After replacing battery then it's still not working, before order a new FOB, I advise you to read this link, it may help you save a couple hundred dollars
http://www.designnews.com/blog/Made_by_Monkeys/13130-You_Want_What_for_a_Replacement_Key_Fob_.php

the dealer gave you a ignition key, instead of valet key.
valet key should open the driver door and ignition. nothing else. if the key can't ope the door. try the trunk. if it open the trunk, the it is a wrong key.

try to unlock all doors with key if don't work try to wiggle key while unlocking the doors or hatchback!!!