Someone has done it again! Reverse polarity jump 2016 Prius

best you can do is get a prius aware scanner, read the codes and follow the sevice manual trouble shooting.
salvage parts will keep the cost down. this is not usually and end of life issue

 

The car needs to go to an experienced electrical technician. It's impossible to tell what you fried. Most likely the ECU is fried. A scan tool may not even work on the vehicle at this point.

 

Note to self, use a jumper kit/battery tender that has polarity detection. It might save a lot of headaches.

However, before that note was taken, I did put an old school battery tender in reverse polarity on my 400cc ATV at the cottage. It stayed like that for a month! When I noticed it (ie, didn't start, duh), I unplugged it, unplugged the battery (battery was showing -5V!), used my boat battery to see if the ATV logic was fried. Nope, ATV was fine, phew. I then on a hunch decided to tender the battery with the correct polarity. Took over a month but the battery went to its nominal voltage and lasted over a year.

 

Huh polarity detection??? It's called paying attention before you put the clamps on. Takes two seconds to look before you connect it. Not only are the posts usually a different color and size, they are labeled with a + and - sign. Match the color of the clamp in your hand to the color on the battery. Really no offense but it sounds like you should just be staying away from electrical systems......

 

i think the op did his mia culpa's, now he needs our help

 

Nothing anyone here can do unfortunately, and if the op has a history of swapping polarity, they aren't fixing it themselves either. Car needs a specialist period. Best to stop blaming it on polarity detection or anything like that and take the car to someone that can fix it.

 

If your engine ran after, it isn’t the ignition circuit of course. You may be ok, go with the hope the fuse did it’s job.
I guess you would have fully charged the battery and now will see if everything relearns itself.

 

I connected the positive lead to the + and negative lead to the -, but I didn't notice that the cable I used for the tender (it had different cable end, depending on its use) was for a different tender and the red plug ended being negative and the black one positive. Anyway, mistakes happen and that's why most if not all battery tender and booster now have polarity detection to prevent connecting it the wrong way. I old co-worker of mine is now deaf in one ear (happened in the early 90s) because the battery of a car he was boosting exploded from such an error.

 

Welcome...
You being able to start the car is a good sign. Disconnect the negative battery post cable for 15-30 minutes. This should clear most of the codes from the mishap. Fire-up the car and drive it around the block. See what codes come back and start tackling them one at a time.

Hope this helps...

 

Well hopefully third times not the charm and you learned to double check all your connections from now on regardless of polarity protection or not. If the car starts and doesn't recognize the key you may have wiped the ECU. That's easy to reprogram..I would see if it drives, many times the warning lights go away after a drive and a couple on off cycles. If not you need a technician.

 

Believe it or not but most of the time the ecus are fine. They have protective circuits to shunt reverse polarity and blow fuses.

Check every fuse and fusible link one by one and carefully reinstall each into the right spots. Several people have screwed this up and have left a fuse holder empty or installed the wrong fuse. Check all fuses and fusible links in the interior and engine compartments. There should be big 60-140a fusible links.

Then power cycle the 12v battery and try again.

 

At least with the stock Yousa on our ‘10, it was pretty subtle. There’s embossed plus and neg symbols on top of case, no colour difference, near-impossible to make out in poor light. You can improve this with a bit of paint, or market pen.

Posts are, well, metal colour, with one a wee bit smaller. The main clues might be red cap on the positive post, and from the other post a cable runs a very short distance, to car body.

 

It's still clearly marked in more than one way with both colors and a positive and negative sign. The red and black are universal industry standard. Still it takes like two extra seconds to double check your connections before plugging it in.

 

Maybe you should check who you're replying to, I'm not OP. Mine was an ATV, not a car

 

Silly forum lag I could have sworn I did. I thought it was op and they already fried one atv battery and now had their sights set on killing their Prius too . I was like how many times this person have to kill a battery before they learn . But it's def easier to swap polarity with the battery out of whatever vehicle it's in.

 

Hey @Geoff Hejde I am in the same boat (Accidentally reversed jumper terminals on Prime 2020 | PriusChat), just did the same thing so it happens to other people as well if that makes you feel better.

Do you have any updates in the situation that might be useful for me as well? Thank you very much!