possible reasons for red triange/how to fix

i started getting it last year in March. Turned car on, barely started to drive, high pitched sound, triangle,, power steering/brakes went out, eventually the engine died, not right away.
AutoClub came, did something quick under the hood and it worked fine for one year.
Toyota replaced 12V at the time of the March 2018 incident.

March this year, it did the same thing, AutoClub rep on the phone said 'he probably reset your battery' when i tried to explain what the guy did the year before. AutoClub guy who came did something quick under the hood and it worked normal again.

Since then, it has done it about about 5 more times, seems to be getting more frequent.

The last few times, without AutoClub, the car came back on after i turned the engine off and on a few times. i don't know if turning it off and on was a coincidence, if it would've come back on regardless. i know zero about car mechanics.

It did it again last week and it did it today. i'm scared at some point the red triangle won't disappear. i wonder if there are any clues anyone recognizes, any patterns that suggest any possibilities. Or if there's no way to know without codes.

The only thing these incidents had in common that i am aware of is, each time it happened, it started right after starting the car, it hasn't occurred while driving. it's happened the next day after not being driven, it's happened in parking lots that i drove to, when i came back out to leave and started the car, it's happened after sitting in the hot sun and after being in the cool garage.

from googling, i saw you tube videos about global battery reset, i'm not sure if this is the same thing, or if a car can reset its own battery. video said the car gets a software glitch, data corruption. Can that be repaired so it won't keep happening?

i would like to be able to read the codes because i understand they can be cleared before i could get to a mechanic after the car has righted itself. I have a mac, so techstream can't be used, at least not by me. Some people on another red triangle thread were saying scanners that people buy don't work for Toyota, not accurate or adequate to diagnose. Someone else said there is a Denso one that is good. i looked on Amazon, there's a Denso one for $450, that's a lot. There are some other brands under $100 that if i understand right, are not adequate for my Prius? It would be a valuable thing to have.

 

i don't know that any repairs were done. at the time i thought he did something, each of the first two times which were a year apart, but whatever it was, it was less than 5 minutes and he was done, car worked. now, after it has come back on on its own, i think if AutoClub had not come and if i'd tried to turn it on, it would have come back on. The other times, the car seemed to come back on, on its own, as if it had been heated and then cooled off---except, it has done it on starting after being cool in the garage all night, it did that this morning and on one or two other occasions.

 

i agree. I mean, if there was some trick to getting a car to start when it had the symptoms mine had that the AAA guys all knew about, that's one thing, but i'm not sure anything was done. i don't think so, after finding that the car just inexplicably starts again, a few tries to start it with triangle, then voila, no triangle. no repairs.

 

In early June i had a weird symptom where while driving, i felt the accelerator pedal stop having an effect, engine not getting fuel, pulled over, it was getting a little fuel, enough to move it but if i kept pressing, the gas didn't increase and didn't accelerate. i got towed home, next day i had it towed to a nearby mechanic recommended for Priuses (on NextDoor in my neighborhood). that was a bad experience. she didn't have the right software, had to update her software, causing a long wait for the diagnosis. then i was given an estimate $6500, including the transmission i think. i have notes on it somewhere. she said i could just get the $4500 part of the repair done. The other part could wait. Something about a lot of dirt and debris built up on the hybrid battery, fan, etc. and a long list of other things. No info on the acceleration. The codes she got, i posted on PriusChat, it was agreed that they were incomplete, lacking needed detail, and her software was not right. i picked up my car--they said that for now, the accelerator was working, but that i should not drive the car at all, no way, it was on the verge of being ruined if i drove it at all, i had barely caught it in time. i got some reassurance here and encouraged to contact Avi at HybridFix Avi said that the accelerator thing, when it happens, just turn the car off and back on and it will work again. i took my car to HybridFix, car now operating apparently normally. It had no codes. Either the other mechanic had deleted or cleared them, or they were just not showing up. The car has not had that symptom again. Avi helped me a lot by telling me that i could turn the car off and back on to get the accelerator working if it happens again, instead of having it towed.

(by the way, about that mechanic who said the hybrid battery was all full of dust and debris so it couldn't cool the battery, even though she said the battery itself measured ok, I have a receipt from Toyota the year before when i first had this red triangle, i took it to Toyota the next day and i don't know if they read any codes because i didn't know about codes then and didn't ask, but they said the cause of it was low voltage on the 12V and they replaced that.
The receipt also shows they did a hybrid battery cooling system service, cleaning everything off that the 'mechanic' said had not been cleaned in a long time)

Now, i am thinking that some kind of reset happens with my car when this current problem of happens, so that it can be turned back on. And i think there might not be any codes by the time i get it to a mechanic. That's what happened when i took it to Avi.

i wondered if it was related to overheating and cooling off, but twice it's done it first thing in the morning, start the ignition and immediate red triangle, as i'm backing out of the garage, i can feel the power steering going out, pull back into the garage. i turned it off and back on a number of times. Eventually, it came on with no red triangle symptoms. That doesn't sound like the car heated up and then cooled off, does it?

when the accelerator pedal acted weird, people on PriusChat advised checking the inverter pump. i could see fluid in it. Also those people who quoted me $6500 to fix it didn't see a problem with the inverter pump, i went to them after checking with PriusChat and being told to check it. When i went to Avi right after that, no problem with the inverter pump was mentioned.

 

She has 80K miles on her.
i know little to nothing about codes and readers, i will check the torque app, can't hurt, thanks!
as for getting an old pc laptop, i haven't used windows in some years, i'll see if i can find a usable one.
first try torque app.
when you say 'take the codes to be read,' do you mean like take the car to Toyota? Will they read them
while i wait? i was reading another PriusChat conversation today about the red triangle, someone was
using a code reader to clear the codes so they could start the car without the triangle, but he was not able
to see the codes. he was trying to find out why clearing codes that weren't there would fix the problem and someone told him codes are there but his reader can't read them, but it can do a global reset of the codes, something like that.
so i was wondering if when my car starts without the triangle, after several starts that continue to have it, has it
somehow reset something? would the codes still be there if i take it in tomorrow to have them read?

 

i had a dog, he died in April. Before that, i'd taken him to a vet about once a month, sometimes twice, for several months. Is that enough to get in the fan and keep the fan from cooling properly?

last year, Toyota removed the HV cooling fan assembly, cleaned the blades, module and ducts, and replaced the battery filter. i don't know if it had ever been done before, I've had the car for 10 years. If they cleaned it last year and replaced the filter and my dog only rode in the car a little bit, do you think it could have a cooling problem months later (now it's been a year and a half and it was March this year that the problem started again. How often does that fan need to be routinely cleaned?

when PriusChat people told me how to check the inverter fluid, they told me to have the car in the Ready mode. I thought it was moving a few months ago. I'll check it again tomorrow. Does just the idling of the car cause the fluid movement to be visible if it's working?

yeah, i know those people were crooks. that's the worst i've ever experienced. sad.

 

Thanks for info and advice.

Torque Pro isn't made for iOS, only Android, according to a website called Scanner Answers. They list two apps for iOS , the best rated by them is OBD Fusion which has both Android and iOS versions. I will go to the OBD Fusion website, it isn't clear whether it's good at reading Toyotas. Learning curve for illiterate me. Interesting to learn though.

if i understand right i need an app on my phone (which on this site says i can use a wireless connection) and i need some kind of hardware thing that connects to something, the car or the phone or?, like you said, a dongle the app's website says it works reliably with. i will try to get some answers about how it works with Toyotas, i haven't landed on the right search terms yet.

To confirm--so a repairer needs to see the car while it has the fault--they need to see my car while it has the red triangle. If it doesn't have the red triangle, there probably won't be any codes for the fault that has happened, unless there is history stored. When i had the different problem with the accelerator losing contact with the fuel, the onset of that symptom gave a short beep. By the time i got it to someone who i know had the best scanning software, there were no codes at all evident, no history, and it was as you say--that nothing could be done.

it sounds like you're saying that trying to repair the fault would be trial and error, groping in the dark. Some have said a most common cause the symptoms is a failed inverter pump. If the fluid is visible moving around in the tank when the car is in READY mode, the inverter is ok for now.

And at that point, it sounds like there are some unknown number of possible causes. that sounds unpromising.

improvement over not knowing anything. I need to get some way of reading the codes while it's happening.
do the codes specifically indicate what the problem is so it can be repaired, or do codes suggest general directions to look in?

thanks!

 

i tried to check the inverter fluid, it was hard for me to see and i'm not sure. Maybe the tank is getting a little opaque from aging. i couldn't see where it was coming up to. Started in READY mode. far from sure about the level. with the car turned off, i took the cap off and looked in with flashlight. i couldn't judge where the level was coming up to. i could see it there, it was up to the narrow part of the neck. i could see a pinkish clear liquid. From outside the tank, i would not have known it was pink. i thought maybe it's not pink because it's completely empty but a level can be seen in the neck of the tank at the top.

i watched a video about changing the inverter fluid on an 2007, the guy was just learning about the car, it seemed like his first Prius. When he was done changing the fluid, he then wanted to turn on the inverter pump to test if the system was working. He said you turn the inverter pump on by hitting the start button twice, it starts the pump. There was a bubbling sound from in the tank, and he pointed out you could hear the pump. is doing this useful? if i pushed the starter button twice and i could hear the pump, would the fluid likely be moving? Can that method be used to find out if the pump is working or could it turn on and still not be able to pump?