Are you in a contract/service agreement with this alarm ?,
I ask because the flashing fault icon suggests that you are,as engineers mode has been enabled, and is active.
This basically means, you need the engineering code programmed in by the installer/engineer if you wish to correct the fault.
I can tell you that the 04 fault you described, isn't a zone fault, and relates to a low system battery,its a system fault code.
Take a closer look at your keypad display, what looks like an 0 is infact a system symbol.
I have a working experience with the matrix and associated keypads,so iam pretty sure about the fault code.
e manno, May 2012