2005 Prius dead

Hi Richard. This wont have hurt the traction battery. When the car is not ready the A/C will only run the fan (and drain the 12V). Everything here is pointing to a simple dead 12V batter (that's possibly escalate after a failed jump start).

+1 to uart.

All signs point to 12v battery failure. You had an original aux battery and drained it many times, it should have been replaced every 3-4 years as preventative maintenance. On a Prius, if you connect the battery terminal backwards or hook up the jumper cables backwards (it happens), you basically fry everything. This is what you are seeing.

Did you have the red triangle of death when you took the car in the first time? Also damage to the HV cable isn't related to any of this. Unless they damaged it during this mess, or something ate through it in your garage, but it is not related.

Before the tow, AAA did try (and failed) to jump the car from the battery and not per the owner's manual ( I was on a plane at the time)..... The first thing Toyota did was put the 12V replacement in and it trained instantly.
They tried that a few times and the 12V kept draining. Seems odd that AAA would not properly hook the terminals up for the jump. Also--the car died (went black) before the jump.

Somewhere in what the dealership is telling you lies the truth.

You cannot drain a battery instantly. If you start the Prius and get into READY mode, then the systems are OK. It does a check before it power on. If the dealer installed a new battery (or multiple in this case) they should know the Ah capacity of the battery, the time it took to discharge from voltage A to voltage B and determine the drain on the system. Or just hook up an ammeter in series with the new batteries. This will show exactly how much current is coming out of or into the battery. When off, you should read current out of the battery. When READY, there are no instances where current should be flowing out of the battery, only into the battery. The value of "instantly" makes the diagnosis different. If instantly really is within seconds, then there is a dead short somewhere. If instantly is installing it in the morning and then the next morning it was dead, well that could be anything.

AAA has mechanics like anyone else. They hook up a jumper box and that's it. People make mistakes. On normal cars you get some sparks and instantly that tells you this was wrong. Then you swap it and all is well. On the Prius you don't get sparks, you get a multi-thousand dollar repair bill for a blown inverter which is what you have. How that happened is anyone's guess. But multiple jump starts is a giant red target saying it was a reverse polarity jump start. These systems are extremely reliable. The few failures that crop up, people try to find the root cause. So far except for a couple cases it is all external problems. Rodents chewing through cables, front end crash damage, and of course reverse polarity jump starts.

Thanks for all those that contributed. The service department attributed it to a failed Toyota part. I enjoyed the 185+K miles and ~5500 hours in the vehicle.

Which part??

Did you decide to get rid of the car?

True, ACC or IG-ON will only drain the 12V battery. "Ready" but shifted to Neutral will drain the traction battery.

I have a Gen 1 Prius with a failed Toyota part. The failed part is the inverter that failed when AAA JUMP STARTED IT BACKWARDS.

bummer...
richard and patrick:
I think my inverter failed before AAA was involved-- I was not there for the jump but all circuits were dead before they got to the scene. I took the opportunity to sell the car for "near" blueblook (it had a lot of paint damage and a lot of "hiking" damage and is still "dead"). Today the car is still on the dealer's lot --dead to the world after three weeks. I returned yesterday to get my CDs out of the CD player. It had enough juice to do just that but not much else. The dash is still full of red lights.....with a 12 V replacement and the wiring harness repaired. the good news is service has to work out the invoice with the dealership and I am free and clear

Thanks for the update.

Ok, thanks for the update. Actually just yesterday I was thinking about your original post where you said "backed out of driveway, drove down the block, Prius stopped all systems dark" and was thinking it might well have been a system failure rather than just the 12V. I say this because once the car is in ready mode the 12V supply is no longer dependent on the battery, so more typically 12V issues result in failure to make ready (or getting weird initial states on ready) rather than dieing while in motion as per your case. So you may well be correct regarding a the fault being entirely unrelated to the jump attempts.

BTW. What are you getting to replace it?