Hyundai Elantra MD/UD: ACC(Accessory)
with manual transaxle
Press the engine start/stop button when the button is in the OFF position without depressing the clutch pedal.
with automatic transaxle
Press the engine start/stop button when the button is in the OFF position without depressing the brake pedal.
If you leave the engine start/stop button in the ACC position for more than 1 hour, the button is turned off automatically to prevent the battery from discharging.