Oil Lo and flashing oil light

[Dazza63]

I was sitting idling this afternoon for about 5 mins when my D40 just shut down I restarted it and noticed the red oil light flashing then I seen the Oil Lo on above mileage. I restarted it several times but it shut down each time. Checked the oil and it seems fine. I have read a little on here about it what I could find. But not to sure on the remedy for it. I have read door open and ignition switched to on for 5 mins or leave it locked for 5 mins then unlock it. I just would like to know if it s serious issue that I can sort out myself or is it a bit more take it to Nissan. I just dont like the shutting itself down part a good thing I guess but never had trouble before. I have just completed a 1500klm trip to NSW last week no trouble at all. Any help grately received and thanks for any you may give.