DTC C1657-87: CAN Time-Out TCS: General Description
WARNING: This page is about a different car, the 2021 Kia Seltos. However, it is still accessible from the selected car via links, so may be relevant.
It is used for checking the vehicle speed in BCW system and identifying either stationary object (guardrail, tollgate, post) or the opposite vehicle in case of detecting the opposite vehicle at the time of acceleration or deceleration.