There was an SIB on the oil sensor reading being faulty, due to moisture in the oil. Not exactly what you are seeing, but it could be similar, and may provide a starting point in diagnosis. The sensor measures capacitance across two plates in the oil, determining the relative degradation of the oil as additives are depeleted. The same sensor also measures oil level. I would assume that there could be air or moisture in the sensor, or crud, causing it not to be able to read correctly.

I'll do a search for the SIB.

Found it:

Attached Images

SI B 12 05 07 Low Oil Level Warning Message is Displayed.pdf (53.3 KB, 1016 views)

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