Monitor Description
WARNING: This page is about a different car, the 2006 Lexus RX 400h. 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. In this diagnostics monitor, the HV control ECU checks the communication bus off count and the message register of the CAN (Controller Area Network) controller. If the HV control ECU detects an error in the communication bus off count or message register, it will conclude that there is a malfunction in the HV control ECU. The HV control ECU illuminates the MIL and sets a DTC.