I've read a few posts on here regarding the SRS light, and it seems the only way to reset it is to take it to the dealership?
I can't say for sure why mine came on. There's a couple of things to mention though...
1. The plastic cover on the passenger side dash recently cracked. I want to say it was possibly due to the heat. As far as I can tell, that's the only thing that I noticed around the time the light came on. The bags have not deployed.
2. I recently had to change the alternator. The lower 14mm bolt that anchors the alternator is so close to the chassis that I have to unbolt the SRS sensor that sits right near it in order for the bolt to the alternator to be removed. All I did was undo the two bolts to the sensor in order to move it out of the way a little.
I also have an actron scanner, which I've hooked up to the car, but it doesn't register the sensor. I reset the codes, but it made no difference.