Maybe as simple as resetting the BSI and then re-synching the key fob to the car. Have you tried that yet?
Procedure for Initialising the BSI after key learning
1. Disconnect the diagnostic tool.
2. Put the driver’s window down, lift the bonnet and ensure all
equipment is switched off.
3. Ensure all doors are closed and remove key from the
ignition.
4. Wait for 3 minutes, disconnect the vehicle battery and wait
15 seconds.
5. Reconnect the vehicle battery, wait a further 10 seconds (do
not open doors.)
6. Switch on the side lights through the driver's window.
7. Switch on the ignition and check system’s functionality.
8. Hold lock button on key down for 10 seconds.
9.remove key open & close door test central locking system
10. Start the engine and complete the system’s check.
Also check the battery in the fob, pop a new one in.
Sim