Takata and others
The ACARS msg content is that ADIRU:s reported air-speed values disagree. Pitot problem is only one of many possibilities. The error can occur anywhere between the pressure on the pressure transducers (dynamic and static) and the computed speed value produced by the corresponding ADIRU. It has apparently happeded that ADIRUs have malfunctioned (their IR-part) and the error not properly detected/saved by the BIT system (on a Boing, however). Don't look at only one possibility, please.