Reversed Jump Start

check the 12v health, then check the fuse continuity

 

if it was me I would just jump it out. Bust out the plastic cover and solder across it. See if the car starts. It may have a blown inverter.
It took a real good reverse polarity. Thats a big fuse. I say just jump it because the car could be severely damaged and best to know now without spending anymore time and money on it. if it starts great then replace that fuse block correctly.
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Your probably jumping directly to the 12 volt battery in the hatch..

 

Your photo is very standard for a reversed jump start. A blown fusible link and a couple blown fuses. Replace them and the car will very likely fire right up.

Yes, you can remove the plastic cover and jump across the open link. I've done it before by wedging a couple pennies on each side. (not my car) Actually, three pennies on driver side and 5 pennies on passenger side. That will get you going, but please don't us it as a permanent repair, lol. One big bump in the road and pennies may go flying.

 

First how are you jumping the battery?

You need to read the OBD codes its throwing. I guarantee its throwing some. It will tell you what system its unhappy about. Did you pull every single fuse in the car the engine box and the kick panel box in the cabin and test with an ohmmeter?

When you say it starts does it drive? or its just throwing these flashing lights and you are calling that starting.

Starting means the word READY is shown on the dash and the engine starts.

 

I don't know if this info will help or not.

A loss of 12v power will cause:

1. fuel gauge to flash one dot until it recalibrates (could be 2 minutes or hours)
2. loss of radio presets
3. loss of driver window auto up/down feature

Low 12v power will cause the squares around the gear indicators to flash (I've seen this happen when battery voltage was around 8-9 volts.

I'm pretty sure the last time I helped someone who reversed jumper leads, there were 3 blown fuses in the underhood fuse box, in addition to the blown fusible link. Checking them all again is inexpensive.

The power source ecu may be involved in this issue. May want to search that subject and see if any similar symptoms are mentioned..

 

Nowhere to rent tech stream.

Your going to need a hybrid capable obd code puller no matter what.
There's VXdiag or mini vci or phone apps Dr Prius or Torque. Use the search forum tab up top and search all those for what fits you best. I have TS and VX. VXDiag on amazon is plug and play mini vci not so much. Both use TS both require a laptop.Phone apps are not TS but will work to pull the codes.

Whats the voltage read at the front jump point to ground with nothing attached to the front jump point? Then turn on the headlights in high beam and while there on read the voltage again. Post those 2 back here. Its probably ok but if I was called there thats the first thing I would do.

Ground is the bolt head right above the black box.

This is why i always recommend do anything you can to keep a healthy 12 volt battery in this car because jump stating it is extremely dangerous to your wallet and sanity. We have seen this scenario hundreds of times on this site.

 

Check your 12 V battery and charge it up* if it is 12.1 V or less. A new AGM battery should be holding 13.1 - 13.3 V when fully charged.


* Or load test it and replace it if necessary (under warranty) – maybe your new battery is defective, especially as you mentioned it was only 11.88 V at one time.

 

George,

Thank you so much for jumping in. I was reading about the issue online and discovered the stoopid thing has an immobilizer complete with its very own fuse. I'll be checking your idea and this fuse as soon as I'm alone tomorrow. It's not technically "working" on a car if that's a I'm doing is it?

Thank you again. I'll let you know.

Posted via the PriusChat mobile app.

 

Hey folks. I've seem to have run into the sane problem. My da jump started the car from the front terminal, the donor car had its polarity reversed, and disaster. The lights were forced on with the switch gear off.

None of the lights work, except for an engine light and the audible brake pump when I try to start it. I've no idea what fuse to test with a phase tester. The 12v is fine now. Perhaps the ignition fuse I'm trying to find inside the cabin.

 

These things happen. They typically result in some blown fuses. Not necessarily any other serious damage, but one kind of has to find the blown fuses first, and then find out how everything else held up.

There isn't a fixed recipe for exactly what will have blown in each car this happens to. There are some more and less usual suspects. You can follow a thread about DMAndy's 2006 that makes a good illustration of how the sorting-out process can go. As you can see, it starts with the wiring diagram, which DMAndy looked up and made frequent reference to.

A caution against viewing the sequence of posts and steps in DMAndy's thread as a fixed script. If you read closely, you'll see that each later step in a later post was a response to whatever DMAndy found and reported in an earlier post. The pattern is look at the diagram, identify something you can check, check that, get your result, look back at the diagram to see what your result tells you, then pick a next thing to check. The exact sequence of steps you'll improvise depending on what you find from one step to the next.

 

{UPDATE} Hey so several weeks la-ter; after I had the 100 amp fuse blown. and two small other ones, the main power converter had been affected too somehow. With a new 100A it resurrected the car with ready mode on, coolant pump working fine etc, the Screen had two or three red square engine warning lights all over, and after 30 seconds just one red 12v battery square.

I had the car's power converter replaced with one from a parts car for 50 dollaroos, and then it keeps on running.

 

While this "worst-case scenario" sometimes is the case, more often than not the 100 A fuse does its job and saves the day.

But it is worth noting that the inverter can get damaged and need replacing.

 

Thanks for this. Helped out massively.
Jump leads were hooked up wrong way round to prius this morning. Spent all morning replacing battery then checking all fuses. Found a couple gone but car would still not come to life.
Resorted to trawling through forums for some kind of idea.
Found your photo of the fuseable link in the busbar. Checked under the now quite yellow plastic cover and hey presto problem solved.