Circuit Description - DTC P3140 - Information Code 351: Notes
WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
The HV ECU records the information code 351 and gives warning to the driver when it detects an open circuit in the interlock signal circuit while the vehicle is running. In this case, it does not shut down the high voltage system.