DTC Description
WARNING: This page is about a different car, the 2021 Hyundai Kona. However, it is still accessible from the selected car via links, so may be relevant.
Checking output signals from both Stop lamp switch when all of them are On or OFF simultaneously, if abnormal signal is detected for more than 60 sec., an error is recognized. And if this condition lasts for certain period, ECM sets P050400.