It's a tire sensor, it doesn't render the car undrivable, it's just a light on the dashboard. Check the tires yourself dumbass, and ignore the light if you don't want to blow $150 on it.
Oh, another rant, DUmmies the gas station is not ripping you off for air, you pay for the air compressor to pump your tires, you want free air, take the cap off the valve stem and blow. (I can bet without looking that some dummie will bring this up).