On that car, it doesn't have a Fast Idle Thermo Valve (unless I'm very mistaken), which would normally be my guess. Your car just has an Idle Air Control Valve, which does the job of both the FITV and the EACV (E for electronic)on older cars.
If you disconnect the electrical connector on the IACV (located on intake manifold) it's going to make the surging go away, but not necessarily b/c the IACV itself is the problem. Could also be a vacuum leak, one way to check for those is to spray starting fluid around the vacuum lines and manifold w/ the engine running to see if the idle surges b/c the starting fluid is making it's way into the manifold through a leak somewhere. You might have to disconnect the IACV first in order to get a stable idle, so you can tell if, and where, spraying the fluid has an effect.

Also could just be that the IACV needs cleaned :shrug:, but I've never removed or worked on an actual IACV, just it's older counterparts.