There’s a quick test you can run on 2014 and newer Hyundai vehicles, using the latest Snap-on diagnostic software, if you suspect bad ground in the vehicle.
With your scan tool hooked up, go to the System menu then select Engine, at the next screen choose Ground, and finally you need the DC Voltage Test.
The next page will show you detailed information and diagrams about how to connect all necessary leads to the vehicle and how to run the test.
Make sure this is followed then hit View Meter to see the data you need in order to get closer to finding the fault and getting on with the fix.