I use Avionic status to identify all the Class 3 faults ( "A" check item), but you need to have everything powered up, ADIRU's aligned etc, so as not to get nuisance messages.
Ground scan as far as I understand is as near as you are going to get to an inflight condition for the system. This is "The Test" on the big Busses (330/340).
Now that I've read your profile I can see where you are coming from. Once again can only emphasise that CFDS is very good once you learn to use it properly and decipher the information correctly.
Hope this has helped