As far as the error code goes, how did you test for checking the dealer mode codes? Often when in dealer mode, the bike has to be taken for a ride / run before the some of the dealer mode codes appear.
To me, the faster / higher idle rpm could range from a stuck secondary throttle valve butterfly, a cold idle setting malfunction, a faulty fuel controller (like power commander, etc), throttle not fully closing, etc. Start with the things that don't require the tupperware to be removed.
Does the throttle close fully? I'm thinking along the lines of perhaps a heated grip cable, throttle grip end cap / hand guard, etc, preventing the throttle from fully closing.
Also have a look at the exhaust control valve actuator on the exhaust pipe on the right side just as the pipe comes out from under the engine. It is worth a quick look... When you turn on the ignition (before starting) that valve should cycle as a self test. Anything preventing the actuator for full range of operation? Perhaps a twig or stone?