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.
When the IG2 voltage of the battery ECU, which is transmitted while the power switch is ON (IG), is low, the HV control ECU determines that a wiring malfunction has occurred at the IG2 terminal of battery ECU. When the HV control ECU detects the malfunction, it illuminates the MIL and sets a DTC.