DTC B258B-00: External Tail Lamp Front Left Circuit Short To Ground: 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.
Once the Body Control Module (BCM) receives tail lamp switch working signal, it sends the signal to the ICU using CAN communication. The ICU turns on the tail lamp.