Reverse Polarity Jump Start - Gen3 Prius wont Start

Did you get the same battery? Or?

If you're still on the 3 year warranty, or even slightly over, I'd be inclined to bring it in to dealership, let them troubleshoot, and don't mention the jumpstart.

 

Did you test the old battery before jump starting? Making sure it was even bad?

Your car has a recall on the inverter, which seems to have failed on some late model gen3. That may be more the problem than the 12v battery.

 

I talked to a Toyota technician several months ago about reverse polarity jumping. He said that even in conventional cars, reverse polarity jumps can do damage, but in the Prius it can be especially bad because there are more computers.

Good luck and keep us posted.

 

1. If the car has some electrical power then the large fuse at the 12V battery positive terminal is OK.
2. Do your tail lights work? If so the 125A DC/DC fuse is OK.
3. If they do not work, find the 125A DC/DC fuse and determine its condition. It probably has blown, given the lack of power that you reported.
4. Do your passenger compartment lights work? That is not dependent upon the DC/DC fuse. If they do not work, find and verify the condition of the 10A DOME fuse.
5. Regarding the combination meter not working, check the condition of the 7.5A ECU-B fuse. That also depends upon the DOME fuse. Once you get the dashboard working again, see if the Prius becomes READY when you try to start the car.
6. Yes, it is certainly possible that the inverter has failed. If you can get the car READY, measure the voltage across the 12V battery. It should be ~13.8V. If much lower, the inverter is dead or the DC/DC fuse is still blown (see #2 above). If the inverter has failed then try to find a used unit on eBay or a salvage yard.
7. Don't worry about the relays right now. If you get to the point where you have restored more of the power to the car and only a few circuits are having a problem, then you can try testing the associated relay.
8. Yes, you could have your car towed to the dealer, but the dealer tech is not totally clueless - if a problem like an inverter failure occurs and the DC/DC is blown, a botched jumpstart is the obvious cause. Further, the dealer tech has to consult Toyota tech support if an expensive part is going to be replaced under warranty. The tech support staff is not likely to overlook user error as the cause of the problem.

 

The obvious that you've already been told, and might of already been aware, is that a reverse polarity jump attempt with a Prius can be especially devastating in terms of potential damage.

I think the simplest, perhaps cheapest ends to getting a running Prius again might be to simply get it to a dealership, and since you are still under warranty you might want to "Eepkay Itequay Aboutway Ethay Umpjay Artstay." And see if The Dealership would repair under warranty.

Of course you can wrestle with the morality of anything less than full disclosure. And if the symptoms and damage are incredibly obvious as to being typical of a jump start gone wrong, it may be something you simply MUST reveal and sadly that would probably make you liable for the resulting repair costs.

But as we all have known since 1993, when the gates are down at Jurassic Park? Sooner or later you're probably going to have to face a big ugly Dinosaur.

Here's hoping yours isn't too bad.

 

i saw this posted in the 2 gen forum:

 

That information will help the OP.
Story will be to find the fuse.................................

 

I've been looking through the Repair Manual (half heartedly) and I couldn't find 125A DC/DC FUSE, or any similar iteration.

I did find Toyota refers to the under-the-hood fuse box as:

engine room junction block assembly

which is just nuts.

 

It may be internally on the DC-DC converter tho

 

is it in the hybrid battery?

 

The Repair Manual shows the DC/DC fuse is the the thick White wire that plugs in. It is a Fusible Link. Disconnect the wire and read for continuity. If open circuit it will need to be replaced. It should read less than 1 ohm if good.

 

I know that in a conventional vehicle, if you reverse the battery terminal when jumping the vehicle with a cable, there will be a main fuse that gets short and you'll end up replacing that big main fuse and it'll work again. As for the Prius, I think there is a main fusible link that gets blown and need to be replace. Try googling the Prius main fusible link and see if you can find out where the locations at. I haven't looked into this situation further but it's a good start for you to check if you have any blown main fusible link. I think there's one by the trunk battery positive terminal, one near the driver kick panel and one in the engine bay fuse box.

Let us know

 

Unfortunately it is not obvious how to disconnect both sides of that thick white link. The OP might have to remove the fuse box to access one side from the bottom.

In the Prius, that is the MAIN fuse located in the positive battery terminal. That is not at fault since the OP reported some portions of the car still have electrical power.

 

jdcollins5, could you post a page number.

C'mon get with the program, that's the:

Engine Room Junction Box Assembly

 

Considering the original manual likely was written in Japanese, that is not a terrible translation. It is located in the "engine room", it is a plastic block assembly, and there are many electrical junctions within.

 

From the 2010 Repair Manual:



No removing the fuse box for the Gen III.

 

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