Service Oil Message

[Bakis]

Hi All, girlfriend just informed me that her car is coming up with the message 'service oil' on her display screen.

Car has had its 15,000km and only travelled 5,000km since so is there an issue with Ford not re-setting the service reminder or is there a sensor in the oil filter or sump, that can tell when the oil has reached its life span?

Car is nearly 3 years old and only does small trips under 10 min everyday.

Any thoughts?

I'm going to ask ford but i want to hear the non lazy version as well lol.

Thanks
James