What year model is Yours?
This happened to my 2 day old diesel Zafira last July, I took it back to the main dealer and they could find nothing wrong, as I was driving her to Italy 4 days later, as the oil level was perfect told by main dealer to ignore, 3,000 miles and 3 weeks later the main dealer looked again, as the light came on 3-4 more time, and cured the fault by a software upgrade, todate no problem.