2001 BMW 530

This is going to require re-initializing all the keys that you use for this vehicle. Gather all the keys and go to the vehicle. Open the drivers door, get in and close the door. Select a key and insert it into the ignition, turn the ignition on but do not start the car, then turn off the ignition, remove the key and then push and hold the un-lock button, and while holding the un-lock button press the lock button three times, and then release the buttons, at that time all the door locks should lock and then unlock via the central locking. Repeat this same process with the remaining key(s) and when you are complete, opening the doors or starting the car will take it out of initialization mode. This will initialize the keys in order that they are coded to the car if car/key memory has been programmed.