Some items need to be reset after the battery has been discharged or the battery has been disconnected. See chapter 3 for:
Hyundai Sonata LF 2014-2019 Service Manual: Specifications
Specifications
ItemsSpecificationsRated voltageDC 12VOperating voltageDC 9 ~ 16VOperating temperature-22°F ~ 167°F (-30°C ~ 75°C)Dark currentSMK : 3mA / Keyless : 3.5mA
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Hyundai Sonata LF 2014-2019 Service Manual: Repair procedures
Replacement
1.
Disconnect the battery negative cable from the battery and then wait for at least 30 seconds.
2.
Turn the steering wheel so that the front wheels can face straight ahead.
3.
Remove the airbag module.
4.
Remove the DAB module.
(1)
Disconnect the air bag connector (A). ...