When I use the key to unlock the land rover the front drivers door and front pass door unlock, the rear doors will not unlock on either side and the back door will not unlock.

The key will unlock the door using the keyhole and turning the key! This is the fail safe for when there is a flat battery......this does not require any battery power whatsoever! I have used this method with the battery disconnected and locked and unlocked the doors!

Procedure for 2002 Land Rover models:
1. With the doors shut and from inside the vehicle.
2. Turn ignition to position 1 and back to off within 5 seconds
3. Remove key from ignition and press and hold the unlock button (has
an arrow on it) for 15 seconds during this time press the key lock button
(has Land Rover logo)3 times within 5 seconds
4. Release both buttons
5. Doors will lock and unlock to show correct programming has occurred hope this helps

Try holding the key in the unlock position for 5 seconds and see what happens ,could be like a seat with a double system

Check the batery in your remote

yes try unlocking the door with the door switch and if that doesnt work then you may have a bad lock motor on the driver side door..
i hope this helps please rate if you think you are been help thanks...

if there is not a keyhole on the passenger side or rear hatch you may want to tryh an unlocking service. i don't know where you are but where i live they only charge about 25.00.

body control module

No, likely to be caused by the actuators in the lock mechanism failing usually causing the door to remain locked. The boor door can also fail this way, as do the front side doors. Replacement requires the whole lock unit to be replaced at a cost of roughly £60 a lock, and a hours work. Helps if you have small hands. Requires a full strip down of the door and you will need the lock unit, trim clips (a few quid) and a trim removal tool (tenner). You can bodge with a flat head screwdriver, but the tool does help prevent damage to the clips & trim panel.

Does it open from the outside once you have manually opened it from the inside.

I have a 2002 land rover discovery and my passenger front door won't unlock with the interior lock button on the dash or with the key fob. The only way to unlock the door is to pull the handle on the inside of the door. Is the actuator bad?

Please help
Rover2163