Found this info from Dave at triple edge in an older post:
Typically this code will set if the input speed sensor reluctor wheel is damaged and no longer spinning as it should. Since you mention the car is driving ok again this is likely not the problem. I would have the code cleared out of the pcm memory and see if it comes back. This code will turn the check engine light on after two consecutive test cycles while driving have failed. There is another code for electrical problems with this sensor but if the signal dropped out and came back a few times from a poor connection that could also have caused what you have. I rarely see the sensors go bad but have seen plenty of wiring problems cause interemittant connections. There is a larger electrical connector on top of the transmission case you could check and make sure nothing is wrong there and you could also clean it with contact cleaner and blow off the connector ends and see if that helps. I havent seen wire harness problems on the 04+ cars but on the 03 and earlier cars I have seen the wire harness rubbed through under the air box area and cause wires to have breaks or short to something and cause plenty of headaches so you may want to look over this area good also just to make sure it is ok.