Inspect HV Battery Thermistor
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.
Using an ohmmeter, measure the resistance between terminals.
Standard resistance:
1 To 2: 9-11 kΩ at 25 °C (77 °F) .
3 To 4: 9 -11 kΩ at 25 °C (77 °F) .
5 To 6: 9 -11 kΩ at 25 °C (77 °F) .
7 To 8: 9 -11 kΩ at 25 °C (77 °F) .
7 To 10: 9 -11 kΩ at 25 °C (77 °F) .
IF resistance is not specified, replace the HV battery thermistor.