DTC C1816-87: CAN Time-Out SJB: General Description
WARNING: This page is about a different car, the 2021 Kia Soul. However, it is still accessible from the selected car via links, so may be relevant.
The Integrated Central Control Unit (ICU) transmits two warnings; 1st (indicator) and 2nd (indicator + beep) using the turn signal information. It also receives auto light information to control lighting and flashing brightness of left and right indicators (side mirrors).
* (MT vehicle - ICU)/(AT vehicle - PCM/TCM) uses reverse gear information, to detect a vehicle approaching from either left and right side using rear cross traffic alert function.