Just a little information for you. Unless your ECM's going bad (very unlikely just this code is set off..) this code is nothing.

This code gets set when the idle deviates too much from what the car thinks it should. It will either be high or low. High is usually caused by a large power consumer being rapidly shut off, while low is usually caused by the idle speed by it being turned on. What this means is lets say the car is at idle and she sharply turns the wheels, it could be set. Or if she were steering then decided to straighten out rapidly.

Unless it comes back with others, its no concern...