For your safety, the automatic transmission has a shift-lock system which prevents shifting the transmission from P (Park) into R (Reverse) unless the brake pedal is depressed.
To shift the transmission from P (Park) into R (Reverse):
1. Depress and hold the brake pedal.
2. Start the engine or place the ignition switch in the ON position.
3. Move the shift lever.
Hyundai Sonata LF 2014-2019 Owners Manual: Air ventilation seats
The air ventilation seats are provided to cool the front seats by blowing air
through small vent holes on the surface of the seat cushions and seatbacks.
When the operation of the air ventilation seats are not needed, keep the switches
in the OFF position.
While the engine is running, push the sw ...
Hyundai Sonata LF 2014-2019 Service Manual: Blind Spot Detection Unit Repair procedures
Removal
1.
Disconnect the negative (-) battery terminal.
2.
Remove the rear bumper.
(Refer to Body - "Rear Bumper")
3.
Remove the BSD unit (A) after loosening the mounting nuts.
Take care not to separate the bracket from rear bumper when removing the BSD sensor.
...