Monitor Description
WARNING: This page is about a different car, the 2004 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
The HV control ECU performs diagnostic monitoring to verify proper operation of internal and external ECU systems. In one of these monitors, the HV control ECU monitors the power supply for the motor main CPU.
If the HV control ECU detects a failure in the power supply for the motor main CPU, it will illuminate the MIL and set a DTC.