The alarm sounds like E60 (Very high pitch distress sound). It should goes off in 1-2 min. but your ignition will be disable, also your alarm will activate again if someone tamper with it again.

But I just don't know how to activate it manually on E70. ON E60 I can just armed it and try to open the door from inside and the alarm will start, but my E70 doesn't. Does anyone know?

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E70 MY08 3.0si Space Grey, Sport steering wheel, Titanium Grill, Titanium lower grill, Sidestep, and more to come

E60 MY05 525i SE Silver Grey, M5 mirrors, Hartge Classic II 20", Eibach Spring, M Sport Trunk spoiler.