well there is a reason y it came on.... but before you go to the dealer and waiste your time try this....i bet your gas cap is not tighten all the way...after you check it and goo ahahah im such an idiot... you will notice the light will go away after you drive it for like 20 minutes or so...nissan made it easy for us ( the consumer) to figure this one out... but if its blinking then thats when you have the serious problem.
hope this helps