Unfortunately, PRIM2 did not fail, else we would have a PRIM2 FAULT somewhere, which we don't. This is a silent "failure".
Svarin, as I am not smart at all on the maintenance and system fault system that uses ACARS reporting, what is the chance that this particular error message was erroneous? Does the system not get a false positive now and again?
If it does, then typically I'd expect that when the aircraft got to an operating base, the mechanics (you all call them engineers?) would run a diagnostic, find "no fault" and clear the fault or sign it off as "could not replicate via troubleshooting steps A through Zed" or something like that.
With that idea in mind, I will assume that maintenance records, and thus ACARS logs, from all previous flights ( or all previous flights after a given date and time) were available for the BEA to review? Or, did BEA get the filtered maintenance records that were a result of ACARS reporting and subsequent trouble shooting and fault remedy?
I ask this with an eye to anyone being able to reconstruct a trend analysis of various faults, or non faults, related to the systems in question. (When FDR and CVR are found, the importance of ACARS systems fault data may fall well into the background).