The heating and cooling system can be controlled manually by pushing buttons other than the AUTO button. In this case, the system works sequentially according to the order of buttons selected.
When pressing any button except the AUTO button while using automatic operation, the functions not selected will be controlled automatically.
1. Start the engine.
2. Set the mode to the desired position. To improve the effectiveness of heating
and cooling:
- Heating: 
- Cooling: 
3. Set the temperature control to the desired position.
4. Set the air intake control to the outside (fresh) air position.
5. Set the fan speed control to the desired speed.
6. If air conditioning is desired, turn the air conditioning system on.
7. Press the AUTO button in order to convert to full automatic control of the system.

Automatic Heating and Air Conditioning
Mode selectionHyundai Elantra AD (2016-2020) Service Manual: Starter Repair procedures
Removal
1.
Disconnect the battery negative terminal.
2.
Remove the battery tray.
(Refer to Engine Electrical System - "Battery")
3.
Remove the air duct and air cleaner assembly.
(Refer to Engine Mechanical System - "Air Cleaner")
4.
Disconnect the starter cable (A) from the B te ...
Hyundai Elantra AD (2016-2020) Service Manual: Auto Defoging Actuator Components and Components Location
Components Location
1. Auto logging actuator
...