P0AA6 "Check Hybrid System" Help and advice appreciated.

Prius model 2010, ZVW30, 120k kilometers. (approx 80K miles)
Over two weeks ago I suddenly got an orange triangle and "Check Hybrid System" message.
I tried:
- Resetting the error message by removing negative 12v.
- Checked the orange isolation switch on the HV battery.
- Replaced the 12v battery with a new one.
- Checked all fuses.
- Had it checked by Toyota dealer. (P0AA6 with no sub-codes)

The car drives fine, no obvious increase in fuel consumption.
After a few minutes of drivng the display, showing the flow of charge stops showing the little animated arrows, and it is no longer possible to chose EV, eco or Sport Mode, these lights also go out. This is also about the same time that it takes for the "Check Hybrid System" message to reappear once it has been cleared.
Dealer says it's code P0AA6 with no sub-codes.
At first they couldn't find the fault. After a more in depth search they came to the conclusion that the inverter is at fault and needs to be replaced at a cost of €3000 plus labour.
I'd like to have a look myself, specifically the short wave values mentioned by Travis Decker in one of his replies to a similar problem
Travis Decker | PriusChat
- Got a cheap obdII connector. Techstream is reporting P0AA6 with no sub-codes. "Hybrid Battery Voltage System Isolation Fault".
Short wave highest value is showing as 0.03, which indicates a short somewhere.
- Today I isolated the Air-Con high voltage supply by removing the HV cable and fuse from the inverter.
The system still threw the error message, so I guess the cabling there is OK.
- I measured resistance on theinverter input cable from the hybrid battery. Between the side that I presume is negative and the chassis neagtive is 0.0 Ohms.
Is this correct? Does the 12v and HV share the same earth?







I'd be grateful for any help or suggestions (Also with using Techstream as I have no clue)
I've ordered a used inverter, but it's going to take a few weeks to arrive.

If you've read this far, then thanks for your patience and interest!

 

Thanks for your suggestion TMR-JWAP.
I did just that this morning.
Disconnected the Hybrid barrety cable from both the Inverter and the Battery, obviously with the isolation switch removed.
At first I was getting a reading of 0 Ohm between the HV negative lead and the car Chassis.
Then I unbolted the lead also from the chassis

Now I only get a zero Ohm reading between the HV battery lead and the HV cable shielding.
Measured at both ends of the cable.

Can I assume that the HV cable has somehow become damaged and that this needs replacing?

 

Took my car back to the Toyota garage where they measured everything again and confirmed that there is a short between the HV cable and the mesh shielding. Most probably caused by a marten trying to bite through the cable.
There is no obvious damage to the cable but some scuff marks, possibly the HV cable and shielding has been compressed together .
Now I have to convince my insurance company that the damage was caused by a rodent.