Acceleration sensor signal

[Tim]

My mechanic told me that my check engine light was giving the code for the acceleration sensor. I asked him what it was for, he didn't exactly know. I think it might have something to do with traction control or SRS. I really can't find any info on the web about this sensor except the error code. Can anyone tell me for sure what this is, can I replace it and where do I find it. Mechanic said 435.00 for part plus labor.