It's just cold, been doing it every year since I got mine. I asked ford and got this response:
Do you like getting up in the morning in 10 degree weather and springing into action? jeez give the oil gauge a break, it's only electric, you have your other gauges that pop right up and say "look at me, look at me, i'm springing into action and telling you you have fuel." friggin show offs, someone ought to hit them in the grotskies a few times and see how fast they jump up. it's cold, it's shivering, it wants to lay down for a little bit longer until the engine hits about 90 degrees and gives me some heat dammit. You know you have oil, you've been changing it regularly right? Do you hear any grinding noises at startup that would indicate that there is no oil? No, because your engine would choke up cough out a piston, seize and shutdown if there were no oil, before you even noticed me or that squealing b--ch 'check gauge light lit up. I hate that friggin guy, i'm want his family dead, i want his dog dead, i want his mailman, cousin, newspaper guy, mechanic, computer, the guy that sang 'copacabana' dead. I want to break 2 of his kneecaps, and make sure it remembers not to squeal on the cluster nostra. Snitches get stitches, what's the matter check gauge light, you didn't learn that on the assembly line? you little pri*k, if you flash one more time I swear, on my limited edition DVD of goodfellas, that I will cut your heart out with a spoon.
So anyway you can change the sensor if you want.