Alarm System Not Working

[Estatical]

I just bought a use BMW and notice that my remote or key will not activate my alarm system. Could someone help me with this problem?

[MarvelPhx]

You may have to get the key recoded to the car, or vice versa. Check with your dealer.

[morcheeba]

you might want to verify that the alarm is really not activated... it could be coded to not beep and/or flash the lights. I haven't set my alarm off yet (or at least was there when it happened), but opening the windows and waving your arms inside should be easier than breaking a window.

Also, are you sure you've got the alarm? It's an accessory - not standard. If installed, you should have a sensor in the ceiling (you've got to open it up to check).