3.0 litre diesel alarm gone funny!!!

[manna90]

Hi all

I recently bought a used E53 3.0 litre auto sport three days ago. Its been parked since. This morning I used the remote to disarm it, went straight to the tail gate, opened it, filled up the CD changer magazine, closed the tail gate, went to start it and the alarm went off. I closed the doors, double checked the tail gate, then tried again but the alarm just goes off. If you insist on starting the engine, it does start with a rapid flickering of the dashboard lights but the horn keeps on sounding until you switch it off. It allows you to remotely lock, unlock it with a flash of the lights as confirmation only on locking.

Please help, what could be wrong?

regards

Worried Xfiver