I hate to disappoint you but the sales talk about a self diagnosing aircraft just doesn't hold up. Very basically now just for pilots:
you have a wire that goes from A to B. Along the way the wire connects to components within a system. Quite often when 2 components attached to the wire lose contact with each other a fault message will be sent.
the message will name the 2 components that are unable to communicate and quite often the message will add wrg: (wiring).
This is not a statement of a definate wiring fault just a statement that a very basic fault detection system can't work out who is at fault