Just turn the ignition off for a few minutes and then back on. I've had the same oil pressure alert since the 15K service so I had VW and Euroclass (where I had the service done) do a diagnostics check...which revealed jack sh#t. I take Euroclass' verdict that it's electrical as opposed to mechanical and most likely due to something being knocked about. I cannot offer anymore info other than to say I now only get that alert once every few thousand kms and the car seems fine mechanically. Yes that beeping frightens the crap out of you but I wouldn't be too concerned.
Good Luck.
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