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Prius Red Triangle light on and other lights, now car won't go into drive or reverse

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by rose908, Jul 5, 2021.

  1. rose908

    rose908 Junior Member

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    So I was driving after a few days on vacation and my car randomly started displaying the Red triangle and the Vsc light and the exclamation point light. When I got home I checked the 12v battery voltage and it ranged from 11.6 when lights were switched on and 12.2 when off. I heard that is low, but have not been able to jumpstart my car yet. I was going to drive to the local auto shop to have my car diagnosed, but then my car would not get out or park or neutral into drive or reverse and more lights turned on. Other than the 12v battery what could be the problem? I did replace the 12v a little over a year ago, I also replaced the hybrid battery a year ago with a used one that I was told would last 3-5 years. I have driven the car a bit more than average but still less than 15k miles, and there has been a heat wave where I live. Is it possible it could be something else? I will try to jumpstart the 12v when I figure out how, and hopefully I will at least be able to drive my car to get the codes read. I will update later on. How likely is it that the hybrid battery is the culprit? I do regular maintenance and change the oil every 3000-5000 miles or whenever it gets low. I have heard the invertor or relay could be an issue? I know nothing about either of these parts or what they are or what they do or whether my car even has them.

    Any knowledge is appreciated! I will update once I can do more.
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    JohnPrius3005 and SFO like this.
  3. rose908

    rose908 Junior Member

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    Okay, so if this were to make the car start driving again, would it stop working once parked?, is it likely a failure with the HV battery?
     
  4. ChapmanF

    ChapmanF Senior Member

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    The traction battery is one of the places where the cause of a P0AA6 code can be. Other places include the frame wire, inverter, transaxle, or air conditioner. With a scan tool that can read INF codes, you can get it narrowed down to one of those general areas, making the search easier. (All still assuming, at this point, P0AA6 is what you've got, since that hasn't been confirmed yet.) If you don't have such a scan tool, you can read about some other methods for narrowing down the location of the fault.

    That's a code where, even if the fault does end up being in the traction battery, it can turn out to be a repairable fault. It doesn't inevitably mean the battery is toast.
     
  5. rose908

    rose908 Junior Member

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    Okay cool. I don't really know what some of that means. At this point I am just waiting on my dad because I don't know how to jumpstart my car or unplug the 12v battery. Once I can get it on and running I will take it to the nearest shop to get it diagnosed. Will most repair places or auto shops be able to diagnose specifically what part is not working well even if it relates to the Hybrid battery? Or should I go someplace that specializes in Prius cars? Are those other possibilities usually something that requires replacements that are somewhat expensive?
     
  6. ChapmanF

    ChapmanF Senior Member

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    Getting the trouble codes should be the first order of business. Most repair shops should be able to do that, but whatever codes they give you, you might want to post here so we can make sure they got all of them. (Some places have scan tools that won't retrieve all trouble codes in a Prius. Often we can tell, because they will retrieve some code X that means you also have some other codes Y or Z, and the list they give you doesn't have Y or Z, we know they didn't get all the codes.)

    If TMR-JWAP is right and there is a P0AA6 code, you might want to look for a shop with a specialty in hybrids. That's a code for insulation failing in the high-voltage system, and none of it is rocket science, but many non-specialist shops will say "high-voltage system, ai yi yi, not us!".

    If you are DIY or DIY-curious, we've got resources here for narrowing down some of the possibilities on your own. "High voltage" should be taken seriously, and there is some personal protective equipment that goes with that kind of work (especially if failing insulation is suspected), and it's helpful to have some electrical background, but otherwise it's not especially difficult work. Yes, some of the possibilities can require somewhat expensive replacement parts, but not all of them.

    I'm still getting ahead of things, as you don't have the codes yet, and we don't know if P0AA6 is even involved.
     
  7. rose908

    rose908 Junior Member

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    Well, we have a basic code scanner and it didn’t read any codes. We will have it diagnosed in a few days and tried jumpstart it the car with no luck. The 12 v battery is still low and we are getting it tested at the shop to make sure there is nothing wrong with the 12v. I really don’t get why the car won’t drive. When the hybrid battery failed last time it could still drive
     
  8. rose908

    rose908 Junior Member

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    We used a basic code scanner and no code was read. A family member has a full on code scanner that will be able to check how the hybrid battery is doing and other parts and may i bf it around. We unplugged the 12v and plugged it back in and all the lights went away and the car drove fine in the neighborhood. We turned it off and turned it back on again and the codes did not reappear. We will continue driving it within the neighborhood and have the diagnostic scanner check for anything abnormal. Idk what to expect. I think I just expect the lights to all come back on in a day so I’m not risking driving it long distances
     
  9. ChapmanF

    ChapmanF Senior Member

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    There are many more things in a Prius than a 12 volt battery, an engine, and a traction battery, and many, many things that can go out of kilter and set trouble codes, and the computers in the car are programmed to take specific actions for some of those, such as refusing to shift into drive or reverse.

    For some reason, people very commonly want to assume that there's just some small handful of possible problems, and they can use a thought process like "it's not this, it's not this, it did such-and-such one time when it was that, ..." but it really doesn't work that way. The available trouble codes are numbered in hundreds. Really the first step that will cover the most distance is making sure to retrieve all the trouble codes and look up what they are revealing.
     
  10. rose908

    rose908 Junior Member

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    We just had a mechanic use a scanner to diagnose it and he also tested the hybrid battery levels. Nothing showed up for codes and everything is within a healthy range, and the lights are not back on. We are just speculating that the heat may have played a role since its been near 100 degrees farenheit for days and the car had been sitting in the sun and had not been driven for days. We will continue to drive it and see what happens and test it again if the lights reappear.
     
  11. bisco

    bisco cookie crumbler

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    possible
     
  12. rose908

    rose908 Junior Member

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    So the red triangle came on again and after I turned off the vehicle and turned it back on, I was not able to put the car in reverse ir drive. We tested the code and got P0aa6. No specific code, my dad also used an app to look at the hybrid battery voltage. The entire battery said 220.27 volts with a 51% state of charge, as well as some green bars with what I assumed to be voltages. Don’t know how to upload the image on my phone.We will get a detailed code tester to find the further error codes. What should I expect?

    The hybrid was replaced a little over a year ago with a used one that I was told would last 3-5 years. I heard inverter problems are the second most common issue. Honestly, this is just very stressful, I need a car, I thought Priuses were more reliable, but I’ve had what feels like a lot of bad luck with it(really just the hybrid battery… hopefully:( ). Like I just need this car to last me like 3-4 more years so I can save up for a different vehicle, it has less than 130k miles on it and I need it to drive because I need to get to school and work but i don’t want to be spending more than the car is worth to fix it or have to deal with constant repairs
     
  13. dolj

    dolj Senior Member

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    You were lied to by them claiming the repair would last 3-5 years. It's more like 6-18 months. There is a reason Toyota does not mess around with secondhand batteries or do "module replacement repairs" and that is they want their customer to have reliable cars.

    If you want a reliable car, get a new battery installed, and then you will have a car that is reliable for the next 10 (or more) rears. Added bonus you will not need to be looking for another car in 3-4 years time.

    You need to stop thinking about what you need to spend on the car for repairs versus "what the car is worth". Think about what it will cost you to replace the car for something similar and could you do that for less than the cost of your upcoming repair.
     
  14. TMR-JWAP

    TMR-JWAP Senior Member

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    For a while, you should be able to just disconnect the main cable from the 12v battery to reset the car and make it drive again. At some point, the fault may become bad enough that it will lock in right away, as soon as you start the car. Some people have installed a switch between the cable and the battery so they can rest it quickly, and used it like that for many months. Not the best solution, but everyone's circumstances are different.

    The odds are very very high that it's a HV battery issue. There's probably 1000 battery failures for every inverter or transaxle failure. What warranty were you provided when the battery was replaced? Was it a complete salvage yard battery or from one of the large rebuild companies like Dorman or GreenBean?

    130k on a Gen2 is a youngster. If the body and interior are in good shape, this car should have a lot of life left in it. Unfortunately, one item to consider is the condition of the ABS pump. If you sit in the car while it's in ready mode (and radio off so you can hear clearly), slowly pump the brakes until you hear the brake pump turn on, then take your foot off the brake pedal. That pump should only run for a few seconds to pressurize the brake fluid accumulator. Start counting seconds from the time you release the brake pedal until you hear the pump start again.

    If you count to 60 with the pump not starting again, you're in pretty good shape. In a perfect system, the pump will run only after the brakes have been pumped a few times. Sometimes the ABS system develops leakage and the pump needs to run every 10 seconds. This is when the car is rapidly heading for abs failure codes and a $2k repair.
     
    #14 TMR-JWAP, Aug 20, 2021
    Last edited: Aug 20, 2021
  15. ChapmanF

    ChapmanF Senior Member

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    First off, there is an answer waiting for you that is not just somebody's guess. That will be the second INF code stored along with the P0AA6. As soon as you bring a scan tool to the car, or the car to a scan tool, that can read the freeze frame and INF codes, you will know—not be guessing—whether the P0AA6 fault is in the battery, or the inverter, or the transaxle, or the air conditioner, or the wiring.

    Then, plans for what to do about it can be made.
     
    #15 ChapmanF, Aug 20, 2021
    Last edited: Aug 20, 2021
  16. rose908

    rose908 Junior Member

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    It’s a green bean battery. I need to send them the codes with the battery failure cell showing and they said they will come and replace it for no cost. However, I have heard from the mechanic who put in the battery that they will often change it only once because they will only change it if the battery failure is not your fault so you need to demonstrate good maintenance and all(I do maintain it well and have changed the oil every 5000 miles and added as necessary and changed the breaks etc as needed). Sooo yeah. I don’t really understand what you mean when you say check the brakes. I’ll have someone else try to help me understand it. Right now I can’t even get it to drive or move the wheels
     
  17. rose908

    rose908 Junior Member

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    Thank you. Yes, I will be doing that next week, and hopefully it can be figured out and fixed within a week or two as I need a car and it will be inconvenient to have to borrow a car to get to school. Thankfully we know someone who can bring their code reader so we do not need to tow the car. I will update once I know the specific code.
     
  18. rose908

    rose908 Junior Member

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    We got the further error code P
    We got the error code P0AA6-526. Doesn’t seem to indicate what’s specifically wrong still though
     
  19. dolj

    dolj Senior Member

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    You need to cycle the car (IG-ON or READY) one more time and it will set the second code.
     
  20. ChapmanF

    ChapmanF Senior Member

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    ^ This.

    The car posts INF code 526 as a "note to self" so that the next time it starts, it will go through a modified starting procedure and try to identify the area of the leakage, and then set a second INF code.

    So you can definitely catch it at times when there is still only 526. Sometimes people have a mindset of "clear the code and see if it comes back", which of course guarantees they will keep seeing only 526.

    There might be times where, even without such interference, it still somehow fails to set the more specific code on the next start. I can't guarantee that never happens, but I don't think it's common.