DTC B1773-88: Climate CAN Communication Fail (Rear): General Description
WARNING: This page is about a different car, the 2024 Kia Sorento. However, it is still accessible from the selected car via links, so may be relevant.
The A/C control module receives the rear seat control signal via the LIN for control, A/C control module also sends the rear seat control indication requirements through the air conditioning line.