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: Speakers Repair procedures
Inspection
1.
Troubleshooting for Speaker
(1)
Basic inspection of speaker
Inspect the sound from speaker after verifying that the
speaker mounting screws is removed and the wiring connector is connected
precisely to remove vibration transmitted from body trims and
surrounding parts.
...
Hyundai Elantra AD (2016-2020) Service Manual: BJ Boot Components and Components Location
components (1)
1. BJ assembly 2. BJ circlip 3. BJ boot band 4. BJ boot 5. Dynamic damper band 6. Dynamic damper7. Shaft8. TJ boot band9. TJ boot10. Spider assembly11. Snap ring12. TJ housing13. Clip
components (2)
1. BJ assembly 2. Circlip 3. BJ boot band 4. BJ boot 5. Shaft6. TJ boot ban ...