DTC U1004-87: Lost Communication With Hybrid Powertrain Control Module (H-CAN): General Description
WARNING: This page is about a different car, the 2021 Kia Niro. However, it is still accessible from the selected car via links, so may be relevant.
The DCT system uses CAN1 NETWORK and CAN2 NETWORK for communication stability. The CAN communication used to transfer vehicle data.