2004 C240 Anti-Theft Alarm Problem

[EPineda]

Help! My 2004 C240 4Matic started having problem with its anti-theft system. It seems the problem is intermittent - works sometimes but goes crazy some other times. Sometimes I can set the alarm on (3-flashing lights) and turn it off (1 flashing light) with the blinkers. Other times I could not. The panic switch on the remote works on and off also. The alarm also goes off while the car is running/traveling and could not turn it off (it is supposed to be off when the key is in the ignition let alone when the car is actually running). The alarm just keeps going off to my embarassment. I checked all my door switches also, including the trunk by keeping open a door/trunk and turning on the system. When any door or trunk is kept open, I don't get the 3 flashing lights when I tried setting the alarm on. I can only get the 3 flashing lights when all the doors & trunk are closed - an indication that my door and trunk switches are working fine. I can only suspect problem with my anti-theft control module, perhaps it is about to go bad. Could I be correct?? Or is there something I'm missing to check? Can anyone offer some pointers/checks that I could do? BTW, where is the anti-theft control module located in the car? Appreciate all the help I can get from our MB experts/techs.