I would assume after the second warning that jet would be impounded and every part of it would be inspected. I also assume both Boeing and Airbus have protocols for such situations along with international regulations.
I would assume the same. If it was indeed a report stemming from the ACARS unit, I would think after two emergency landings, they would ground the plane and look into it. If it was something simple like a warning light flickering (which is taken very seriously), they would check it. A lot of times, they find that it is just a simple short circuit in the wiring from constant vibration.