All late model cars have electronic Idle air control systems by an electronic throttle system or and electronic air valve. In order to check operation of these systems you have to have good diagnostic equiptment and understand how the system works. On some Chrysler models if the vehicle loses battery power the idle system has to be relearned. This is something a repair shop has to look at and it poses a potentially safety issue with the vehicle idling very low it could cut off.
Remove the plenum going to the throttle body and spray throttle body cleaner into the throttle body while the car is running. Make sure you spray the cleaner into the lower wedge shaped part, this is where the idle control valve is.