Faulty 12 volt battery + possibly nuked electricals

Reversing the polarity on the 12-V battery might have done a lot more damage than only blowing the main fuse given the number of semiconductor chips in a Prius Prime.

 

They knew this from the beginning and were just hoping for a miracle. The main fuse and several others will be blown. They could move faster than their current excuse indicates but they are delaying hoping the tow companies insurance will take responsibility. That is a big unknown but many will fight you.

I will say we have seen this many times before and in most cases the ecus and devices will be ok after all the blown fuses are found and replaced.

Any smart jump starter box these days has reverse polarity protection before power is allowed to flow. The fact your tow guy did not have one or overrode it does not build confidence.

 

There's a fuseable link on the underside of that junction block that's blown. If you find that thread, where someone else here did this; I believe it was mentioned. The dealership just wants to swap parts - unfortunately this will only make it take longer to get your car back on the road. Once the parts come in, I'm sure they will find something else they'll need to order and wait for.
If that dealership valued you as a customer and respected your time and patience - they could've rolled down all the windows and hooked up a temporary battery to diagnose any further issues and order everything they needed all at once, to get you back on the road. They're currently nickle and dime-ing you to see how much money they can milk out of you and the insurance company. IMHO. The time delay tactic is to get you more desperate and to make you say yes to everything, just to get your car back as the car rental bills and inconveniences mount.

Just saying... We used to do that all the time, in the shop I used to work in.

PS. once you get the insurance claim number, call your car rental agency to get your rental bill redirected to that insurance claim center and have them bill past charges to the same claim and have them reverse the charges on your credit card. I've done that in the past and you'll be amazed how quickly your car gets moved to the front of the line - because the insurance company wants to stop those rental car charge claims. I was told two month to get my car repaired from an accident - it was out in two weeks.

 

Haven’t read this entire thread but, just bought my 24’ Prime and was dead went I went to test drive it. They jumped it. I ended up buying it. Before I left I asked if they would replace the battery. Service dep was closed and they said “would be fine it’s brand new” etc etc. Welp ended up stranded a few days a later car wouldn’t start and was acting very strange.
Jumped it. Then charged it with my charger. No issues sense. I still want to have them replace it tho. Very annoying

 

Yea, get a cheap jump pack and toss it in your trunk. Check it once a month for charge status. Read the instructions and figure out how to use it properly. Almost all new jump packs has reverse polarity detection; so this won't happen to you. Unfortunately, tow truck drivers are suppose to know what they're doing and older tow truck don't have those safety's built into their systems.
There seems to be a manufacturing issue with the early batteries, not sure if those issues has been rectified for your 2024. If you can find the TSB for the battery issue, it should narrow the model dates of cars affected.
I check my battery every quarter (3 months) with my certified/calibrated Fluke DVM. It's almost always on the lower passing end of the specifications. I drive this car daily and recharge the traction battery every night. I've never been stranded, but I had to put the battery on a charger on 3 separate occasions, since it was below specifications when I checked it. It only took 15 minutes @ 10A charging to get back into specifications - which indicates a good battery. If it took any longer, I probably would have a questionable battery.
DO NOT use the accessory mode on this car for any length of time - keep the car in Ready mode, so your drawing off the main traction battery. That is one of the ways to kill your starting battery. It's too small to run your radio for an hour or two; but your large traction battery will run it forever - as long as you keep the gas tank full.

Congratulations on your purchase and hopefully that issue was a fluke. I do recommend that you check your battery on occasion, if you decide not to purchase a jump pack. You don't have to rip apart your car, just take a meter reading at the jump point under your hood. Once your familiar, you can prevent a tow truck driver from "blowing-up" your car.
Lastly; DO NOT offer to jump start someone else with this car, that's what roadside assistance or your jump pack is for. You can damage your car from the feedback loop created from the large current draw or current pushed back into your system when their car starts. There are warnings in your owners manual.

 

A good jump starter with reverse polarity detection, was the first thing I thought of while reading about the Roadside Assistance call.
I didn't want to be the first one to post about it, but if 5Gen 12 volts are really as bad as we are starting to hear lately, it might be time to start thinking about recommending them more often for Gen5 new owners.

 

Drove around town on this nice day, battery at 73% soc and charging when got back. On the charger maintainer it went. Sure it would have been fine and started the car fine, but now that I have a device that shows everything I need to know on my phone I want to keep my 12 volt better. I have load tested the battery it is fine.
Best thing I learned on this forum was about the device.

 

Unless I've missed something, the only battery-related TSBs on the 2023 or 2024 gen5s are the standard TSBs that have applied to all Toyotas and Toyota hybrids for many years. All Toyotas have a TSB that says the battery in a new car needs to be tested(and charged if needed) within 48hrs of expected delivery to the customer. And all Toyota Hybrids have an additional TSB that tells the dealer how to maintain both batteries if the car is being long-term stored or has sat on the lot for multiple months. But I'm seeing nothing about a TSB specific to the gen5 battery issues that have been raised in these threads. (I honestly wish there was.)

I'll just link the TSBs below. The ones ending in -22 are for the 2023 models; the ones ending in -23 are for the 2024 models.

 

A lot of cars are being sold with Lojack, a gps device that is connected to an always hot source even when the car is off. Today I reached under the dash by the obd port and pulled some loose wires down. I had read the installation instructions on the Lojack website and saw the hot lead has a fuse holder. There it was on the red lead, very hard to get open and the 3 amp fuse I had to use pliers to get it out of the holder once open.
No more working Lojack on my car. This costs $1200 on Amazon for a 7 year subscription, installed. All a thief has to do is find the Lojack and clip the red or black wire. Later in the summer I’ll take it all out and remove the door jamb label. It is just an obd harness they put in to get a hot and a ground.
So unless one truly needs a Lojack, it might be better for the 12 v if it is disconnected. The police dept where car is stolen has to have the Lojack receiver in their patrol cars, not all do.

 

Previously you posted : "Have to have a battery monitor to know more." and in this comment you write "....but now that I have a device that shows everything I need to know on my phone...", could you comment on the device you use as a battery monitor on your phone ?
And which charge maintainer do you use, and do you dsconnect the battery from the vehicle when using the maintainer ?

 

Any updates on your junction bax main fuse delema ?

 

When people complain about Toyota they should consider the robustness of the twenty some computers which protected themselves from reverse polarity while the main and other fuses blew. It was their protection semiconductors that blew the fuses. Good engineering.