DTC P321E-9F: Motor/Generator Shutdown Signal Stuck Off [04/2018 - 08/2020]: Wiring Diagram
WARNING: This page is about a different car, the 2020 Toyota Avalon and 2019 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
Refer to the wiring diagram for the shut down signal circuit.
Refer to WIRING DIAGRAM