DTC C1503-01: TCS Switch Error: General Description
WARNING: This page is about a different car, the 2024 Kia Forte. However, it is still accessible from the selected car via links, so may be relevant.
Driver can inhibit the Electronic Stability Ptogram (ESP) control by ESP OFF switch.
When switch signal sends into the HECU, the ESP warning lamp goes "ON" and the ESP control is stopped and if the next switch signal is inputted again, the ESP control is ready. This function is used for sporty driving or vehicle inspection.