Inspection Procedure
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.
If INFORMATION CODE 306 OR 307 is output, check if other DTC or information codes are recorded. If they are recorded, check and repair those codes first.
If INFORMATION CODE 306 OR 307 alone is recorded, replace the converter & inverter assembly.