DTC U0134-87: Lost Communication with Power Steering Control Module Rear Missing Message; DTC U1171-87: ECB Communication Error (CAN) (CL-Bus) Communication is Lost [09/2023 - ]: Wiring Diagram
WARNING: This page is about a different car, the 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.