Reading the last thread reminded me of a problem I have had a couple of times.
(This may apply to cars other than the E39)
Apparently, strong radio signals near your car (maybe police/ambulance etc.) can mess up the programming of the remote key operation. When this happens, the car will not recognize the key and you cannot disarm the alarm
This has happened to me twice and once to my brother last week. It's no fun driving through London with the alarm on and all your lights flashing
Anyway, to avoid this situation, I wrote and keep the following method in my glovebox: -
Instructions for Initializing Keys
(When key will not disarm the alarm)
To be carried out inside the car with doors closed:
1 Switch ignition to position 1 for three seconds, then off again.
2 Remove key, then holding the unlock button, press the ‘lock’ button 3 times.
3 Release the ‘unlock’ button. Central locking will lock then unlock. Key is now ready to use.
4 Repeat stage 2 & 3 with other key. Keys must be re-initialized at the same time.
I hope this might save others a whole load of hassle !