Switch Diagnosis

WARNING: This page is about a different car, the 2020 Hyundai Kona. However, it is still accessible from the selected car via links, so may be relevant.

Connect the cable of GDS to the data link connector in driver side crash pad lower panel, turn the power on GDS.
Select the vehicle model and then SMART KEY system.
Select the "SMART KEY Unit".
After IG ON, select the "Current Data".

Courtesy of HYUNDAI MOTOR AMERICA

You can see the situation of each switch on scanner after connecting the "current data" process.

Display	Description
FL Toggle SW	ON: Push button is ON in the driver door handle.
FR Toggle SW	ON: Push button is ON in the assist door handle.
Tailgate open SW	ON: Tailgate button is ON.
Gear P Position	ON: Shift lever is P position.
IGN 1	ON: IGN switch is IG position.
ACC	ON: IGN switch is ACC position.
Brake SW	ON: Brake switch is ON.