The various sensor names/tests get triggered when the reporting system is no longer responding.
The majority of the time, this is when there is a bad DIMM, and it triggers a system freeze, CATERRN
You might want to check your SEL logs to see if you have recently had a spat of correctable, or an uncorrectable error logged on any of your DIMM slot. Usually takes a power cycle, or power drain to get out of that state.
Obvious this DIMM errors would require a DIMM replacement.
Kirk...