Hyundai Sonata Hybrid 2021 Owner's Manual page 264

Engine Stop/Start button positions
Button
Position
To turn off the engine, press the
Engine Start/Stop button with shift
button in P (Park).
When you press the Engine Start/
OFF Stop button without the shift
button in P (Park), the Engine Start/
Stop button does not turn to the
OFF position, but turns to the ACC
position.
Press the Engine Start/Stop button
when the button is in the OFF
ACC position without depressing the
brake pedal.
Electrical accessories are usable.
Press the Engine Start/Stop button
while it is in the ACC position
ON without depressing the brake pedal.
The warning lights can be checked
before the engine is started.
To start the engine, depress the
brake pedal and press the Engine
Start/Stop button with the shift
button in the P (Park) or in the N
(Neutral) position.
START For your safety, start the engine
with the shift button in the P (Park)
position.
Action Notice
If you leave the Engine Start/Stop
button in the ACC position for more
than one hour, the battery power will
turn off automatically to prevent the
battery from discharging.
Do not leave the Engine Start/Stop
button in the ON position when the
engine is not running to prevent the
battery from discharging.
If you press the Engine Start/Stop
button without depressing the brake
pedal, the engine does not start
and the Engine Start/Stop button
changes as follows:
OFF → ACC → ON → OFF or ACC
However, the engine may start if you
depress the brake pedal within 0.5
second after pressing the Engine
Start/Stop button from the OFF
position.
06
6-7