You can relearn the idle without a scan tool if there are no fault codes in the system. Just let it idle for 3 minutes and shut it off for one minute then start up and idle for 3 more minutes.
If the car has fault codes or has high mileage the throttle body may never learn the correct idle unless you clean the carbon from the trottle body. It must be completely clean. Don`t force the throttle body open to clean it. Have someone turn the key on and hold the throttle pedal to the floor while you clean it.
If the car trips any idle control codes while learning the idle clear them and continue the relearn.