Connected Leads Wrong While Jumping Prius...

I've fixed this for people a couple times. After replacing the fusible link assembly on the left side of the under hood fuse box, I've always found 2, 3 or 4 other fuses blown in that box. I just pull every single one, one at a time and check them. Replace as needed, and the car has been fine afterwards.

 

And when buying a fuse assortment- just a reminder, use good brand name fuses. eBay and Amazon are both selling a lot of counterfeit junk which turn into fire hazards. Meanwhile the neighborhood stores usually have the real deal, hopefully they are offering curbside sales there.

 

how to reset the "exclamation point with parenthesis around" and hopefully revive my stereo too. No engine check lights are on currently.

I suspect this is the TPMS indicator lamp? exclamation point with parenthesis and a slightly squiggly line along the bottom (like a tire tread)?

Does it blink for several seconds when you initially start the car? If so, either you have a low tire pressure or the car has lost communication with one or more TPMS modules in the tires. Or maybe the tpms system has no power?

 

To reinforce what Leadfoot said:

 

The various vaguely cube-shaped boxes you see are relays. They are part of what the fuses actually protect when they blow out.

So you've swapped the big white/clear fusible link, now you need to check the branch fuses and replace any that burned at the same time as the big link. There is a secondary fuse panel in the cabin, roughly in front of the driver's left knee. I'm not sure what the access is in your version of the car.

Do the underhood ones first, replace any that burnt out and chances are that'll be a full cure but if anything lingers start checking the cabin panel next.

 

I would think "NOT Connected"

Keyword....."Pioneer Stereo."
Aftermarket unit.
Aftermarket wiring?
I'd find out how this unit was wired into the Prius and try to see if you've got 12VDC going into the head unit.

I'd want to verify that the ((!)) isn't being caused by the 12v battery.
Especially if the brakes feel OK and the fluid level is good.

NEW battery is not necessarily a GOOD battery - especially if the car has been a hangar queen for the last few days and not running and recharging the 12VDC aux battery.
Stick a crow-bar in your wallet and get a battery tender until your car is a daily driver..... ($20 if you can find an open WalMart)

I've used the $5 Harbor Freight units in the past too (they have the same chip in them as the $40 name brand) but the $20 WalMart unit has (or used to have) the semi-permanent, semi-weather resistant under-hood connection that you can use restore the charge in your 12v battery over night after you've had the doors and hood open in your driveway all day.

 

ok, so it's an exclamation mark inside a circle, inside a set of parenthesis? Is it red or yellow?

Have you tried resetting the car again by disconnecting the 12v battery for a minute or two?

 

I like @ETC(SS)'s guess about the NCON message. As far as the stereo not actually operating? I'll take my own guess- it might not have been installed correctly with adequate fuse protection vs. the reverse polarity event you've suffered. That's not uncommon in aftermarket radio installations.

 

Since you don't live near ME?

Sure!


I'd go easy on the first few test flights and probably would refrain from interstate hops and hauling babies for a while.
It's not like your state has an operable "STAY HOME" order judging from the number of people I'm seeing on your beaches......

 

The stereo itself could be toast. Some have an internal fuse, some have an inline fuse on the included harness. Some are able to withstand negative polarity, others just fry. Naturally they all protect themselves by saying "Never do this" in the manual.

So you'll certainly be able to get another stereo to work in this car, but it's kind of iffy for the current unit. You'll want to get it out and check power on the constant & switched 12v lines first, then triplecheck any fuses feeding those lines just to make sure.

 

I reset the 12v and it's gone now! IT'S GONEEE!

 

Did you use the same plug that goes into the actual radio like this? (This is for JVC, so other brands might look differently)

Or did you plug into the loom of 10cm to two plugs like below? (This is for Honda, so the blue plug would look differently)


Reason for asking is because one common issue in carstereo's is the yellow and red wiring and the differences between some brands. Mostly this only causes the radio to not remember its settings when reversed, but I have seen it causing other (not always logical) issues that were solved by swapping them around. In the first pic I posted, you would see bullit-connectors so yellow and red can both go to yellow, OR both can go to red OR red can go to yellow and yellow to red, OR yellow-to-yellow and red-to-red.