2004 verona revs up

A friend of mone has a 2004 verona and it speeds up on its own. revs close to 4000 rpms idling at times. Light came on and autozone pulled code P1512. Any ideas? Thanks

My daughter's '04 verona had surging problems, and would actually stall on the highway. There is a dealer TSB out that reflashes the ECU and solved her problem. This could be covered under warranty.