We have a 2010 Ford Fusion Se, 2.5L V4. My wife primarily drives this vehicle. Occasionally, we get a low tire pressure light on the dash. My wife said she went to a tire place to have the tires filled up yesterday around 5 PM. In less than 24 hours, on her drive back home from work, the tire pressure light came on again. Where/How do I begin to determine what the issue is?