DTC C1704-01: ECU Fail-Safe Relay Fail: General Description
WARNING: This page is about a different car, the 2024 Kia Sorento. However, it is still accessible from the selected car via links, so may be relevant.
Driven Power Steering (MDPS) ECU has a relay to cut off current to a motor if abnormal operation is detected. MDPS ECU checks a condition of relay while ignition ON.