Hyundai Elantra MD/UD: Automatic climate control system
1. Turn the ignition switch to the ON position.
2. Select the defrost position pressing defrost button ().
3. While holding the air conditioning button (A/C) pressed, press the air intake control button at least 5 times within 3 seconds.
The indicator on the air intake control button blinks 3 times with 0.5 second of interval. It indicates that the defogging logic is canceled or returned to the programmed status.
If the battery has been discharged or disconnected, the system resets to the programmed defogging logic.