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 ECU systems. One of these monitors compares read and write values at the inside of the HV control ECU memory, which have been indicated by the transponder key or the electronic key.
If those two values are inconsistent with each other, the HV control ECU interprets this as an ECU memory failure of the HV control ECU. The HV control ECU illuminates the MIL and sets a DTC.