General Information: General Description
WARNING: This page is about a different car, the 2015 Hyundai Sonata. However, it is still accessible from the selected car via links, so may be relevant.
The AHB ECU (Electronic Control Unit) receives gear position from TCM through CAN Bus line to determine that regenerative braking is possible condition.
For example if gear position is not D or sport mode, that means vehicle is not driving mode so at that time regenerative braking is not allowed.