The BSI unit is basically a computer which handles a multitude of functions such as odometer value, central locking, lights and immobiliser. Some later Bsi units are liable to corrupt their own software program if not “woken up” in a specific way after programming keys or battery disconnection. 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. Failure to follow this procedure could result in incorrect operation of many BSI related items. It did take three attempts following this procedure before it worked. This is advice only good luck Andy.