Replying to my own post -- had to search back to 2007 for this. It worked for me culminating in a beep, all door locks disengaged and all windows rolled down. And that then allowed me to use that last known good key to start. Went around the block and just parked up. Haven't tried pushing my luck with the second key fob that never did work (but its blade does manually unlock)
Reset Procedure for Key Fobs
~~~~~~~~~~~~~~~~~~~~~~
reported as working OK for L322 '02MY "Mk III" And my '03MY just now...
https://www.landyzone.co.uk/land-rover/l322-mk3-rr-key-fob-central-locking-reset.45227/
With thanks to Swast4 for this post whey back in 2007
Every signal from the remote handset contains transmitter identification code and a rolling code.
The BCU checks the codes and only responds if the signal is from a valid transmitter.
During vehicle production, remote handsets supplied with the vehicle are initialised to set their
individual transmitter identification codes and synchronise their
respective rolling codes with the BCU. If a transmitter loses synchronisation with the BCU, or if a
replacement or additional remote handset is to be used with the vehicle, the initialisation procedure must be
repeated. During the procedure, all remote handsets for use with the vehicle must be initialised.
Initialisation Procedure
~~~~~~~~~~~~~~~~~~~~~~~~
1. Ensure the vehicle is unlocked and the driver and front passenger doors are closed.
2. Install a key/remote handset in the ignition switch, then turn the ignition switch to
position I and back to position 0 in less than 5 seconds to put the BCU into the initialisation mode.
Continue this procedure within 30 seconds of turning the ignition switch to position 0.
3. Remove the key/remote handset from the ignition switch.
4. Press and hold the unlock button for a maximum of 15 seconds. During this time, momentarily
press the lock button three times within 10 seconds.
5. Release both buttons.
6. Successful initialisation is indicated by the BCU locking then unlocking the vehicle.
If this does not occur, repeat step 4.
7. Repeat steps 4 and 5 with all other remote handsets belonging to the vehicle (4 maximum).
Begin the initialisation of each remote handset within 30 seconds of completing the previous
initialisation, or the BCU will drop out of the initialisation mode and the complete procedure will
have to be started again.
