Exclamation light after 12v change

what's the brake light on the left?

 

That is an electronic brake warning. Not ABS but regen or ecb. Not good. Time to get the OBD codes harvested to see exactly what the car is unhappy about.

Auto parts store may be able to harvest the codes for this but dealer for sure but will be $150 to do that. For $150 go buy an Xgauge you can pull the codes yourself. Wherever you get the codes read make sure you write them down complete with all there subset codes
and post them here.

Is the brake fluid reservoir full? I bet regen braking is not working. Please list the miles on the car.

 

Without a code reader, codes from the brake ECU can be read by using a short piece of wire and counting light blinks, reporting them here. Doesn't have to be big bad news. Sometimes the brake ECU will want to relearn certain calibrations, which is kind of fun actually; you stop in a nice level spot and tell the ECU "ok, do your thing" and you listen to it play little games with the brakes for a minute or two and then it's happy and the light goes out. Remember it was sitting there for a while with no power while you changed the battery.

It could also turn out to be some dreadful brake problem that just happened to crop up at the same time. But either way, you'll know by reading the codes.

 

Or see #4 if you don't have a usable reader.

 

Any chance that something just needs to "re-learn" after the loss of 12 V ?
Have you driven it more than a few blocks yet ??

 

I'm reluctant to ask, but would that be the warning that parking brake is on?

Never mind:

 

Was the electronic brake power supply located at the 12v battery reconnected properly?

 

Post #4 in this thread, regarding the count-light-blinks method to get brake system trouble codes when no code reader is handy.

 

Sometimes around PriusChat, if there's a topic that's been covered to death in years of old threads, we'll just mention it, as a kind of a shorthand. It's not about trying to slow you down or anything, it's just fairly easy to search, and not a lot of fun to type the same stuff over and over.

 

Theres a small amp fuse on the + terminal you could check that. What brand battery? whats the voltage car off and car running?
Before you go to the dealer and spend $ 125 for them to only read codes. You might be better off getting mini vci toyota tech stream and a laptop then you can read every code yourself.

 

And maybe not too.
That tends to encourage people with no mechanical experience and training to just start changing parts without looking at the "big picture".

But then, wait, that is not much different than what happens if you take it into a dealership.

 

Sam's got a point here; once you have your reader, don't be the guy who sees a code like "Pxxyy KANUTEN VALVE" show up on the code reader and immediately thinks "oh, that means I should buy a kanuten valve", because those fortune-cookie quotes that come up on the code reader are not the whole story of what a code means, and the real reason you have the code can lie somewhere else.

But good on you for getting the reader, so you also won't be the other guy who says "oh, maybe I'll read the codes after I run out of expensive parts to throw and my car's still not fixed."

The sweet spot in between those two extremes is around where you get the codes, look up what they are really telling you (the "detection condition", to use the lingo; more info), think a bit and poke around to see why your car had that condition, then fix it.

That way turns out to work pretty well.

 

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