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"Check Hybrid System" P0A94 and P324E w/ ABS C1259 and C1310 (doesn't reset)

Discussion in 'Gen 3 Prius Main Forum' started by HeyMikeyLikesIt, Jan 7, 2021.

  1. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    Hello.

    I read through many existing posts but I'm not finding a solution to my specific problem.

    The other day suddenly the car went into what felt like super echo mode and although it's drivable it's noticeably weaker and has a hard time accelerating when going uphill. But it does start and run and has never shut down unexpectedly yet. (Dash picture bellow)

    I accidently cleared the engine codes using my OBDII Scan Tool but the P0A94 code doesn't go away. (Original codes as well as battery reading bellow)

    I tried to reset all the codes to have the car run normally until the codes trip again (because I wanted to take the car in to get diagnosed and I wanted all the engine codes to re-display) but although I followed several of the instructions in the other threads the P0A94 / Check Hybrid System issues causing the car to be in a weakened state does not go away.

    The 12V batter was replaced about a year ago. There are about 133k miles.

    Are there any suggestions of how I might be able to diagnose this issue to resolve it or how to cause the other engine code to present again? I'm somewhat afraid to drive it in it's weakened state with the Check Hybrid System message in order to hopefully trip the other P324E engine error code to come back but I think that if I take it to the dealership to get diagnosed they wont have all the data needed to properly diagnose it.

    Here is the original error codes before my accidental clearing.

    prius-2010-codes.jpg

    Bellow is the batter reading after accidently clearing the engine codes.

    prius-2010-battery-reading.PNG

    Bellow is the dash after accidently clearing the engine codes as well as trying to reset all codes by detaching the cable from the 12v battery, unclipping the orange clip in the trunk, unhooking the white wire in the trunk, and also turning the engine on/off several times as well as driving around and also turning the engine on/off.

    prius-2010-dash.jpg
     
  2. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    I ran the AC at full and also drove around while taking screen shots of the battery voltage a couple days after posting and here are the levels. The state of charge seems fairly significantly down from 40% a couple days ago. The voltage didn't go down bellow 14.84 so I'm not sure that is low enough to cause this problem?

    Also the engine is always running from the start.

    Any advice on how to further diagnose this?

    IMG-1320.PNG IMG-1321.PNG IMG-1322.PNG IMG-1323.PNG IMG-1324.PNG
     
    #2 HeyMikeyLikesIt, Jan 9, 2021
    Last edited: Jan 9, 2021
  3. PriusCamper

    PriusCamper Senior Member

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    Have you checked in on Gen3 Inverter recall? Is it possible your car qualifies or you could convince Toyota corporate customer service that it applies?

    The other thing is looking into the details of the differences... For example certain driving events that trigger it like a bumpy road or turning sharp, which could lead to a loose plug or connector somewhere?

    Also the voltage difference on the top screen shot is bad, but the difference in lower screen shot is ok... Why the difference?
     
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  4. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    For the inverter I checked Toyota's website using my vin and also called and they said I don't have any pending recall for my car. I'll try to see if I can get anywhere with Toyota corporate customer service. I thought that if the inverter died that my car wouldn't start or run but sounds like that might not be the case, that's hopeful!

    The reason for the differences weren't obvious to me, I started driving around my neighborhood (trying to start and stop with the AC blasting but it wasn't a bumpy road and didn't make sudden or sharp turns), and the first reading was early in the ride the last one was later... it seems like the battery gained a little charge by the end of the ride, not sure if that indicates anything to you.
     
  5. PriusCamper

    PriusCamper Senior Member

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    Best case scenario is that's something is loose and can be easily fixed. I've gotten inverter error codes for loose terminals in the battery pack before.

    As for contacting Toyota, make sure to study the details of the Los Angeles lawsuit that led to inverter recall and present your case to them in that exact context. Also if you do enough digging on this website you'll find the name of a woman who was/is Toyota corporate customer service rep and contacting her would be an ideal place to start.

    Also if you're car is still able to be driven without warning lights and going into limp mode try to get as much data as possible via Dr. Prius, Toyota Techstream and Hybrid Reporter... The more data you have on the inverter the easier the diagnosis.
     
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  6. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    Something loose would be ideal, but somehow I'm not feeling lucky.

    Thanks I'll read up on the lawsuit details and look for that service rep.

    The car is drivable, but several warning lights are on in the dashboard (image in first post) and it's definitely in limp mode. It's slow getting up to speed and engine starts to rev easily but does get there, at least on surface streets.

    Initially I was getting 2 engine codes, P0A94 and P324E, but I accidently (stupid me) cleared the engine codes but only P324E went away.

    Then I figured I would clear all codes to get the car out of limp mode and wait for both to trigger again but the P0A94 code wont go away (along with the lights on the dash) and now I've tried everything including unhooking battery (orange cut-off switch), 12V, and white cable under the hood leading to the box... turning the car on and off several times, driving around, etc.

    Do you think I ruined my chances of getting properly diagnosed by a Toyota dealership or should I just take it there for an assessment?
     
  7. tvpierce

    tvpierce Senior Member

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    Why are you fixating on the battery? The P0A94 code is telling you the problem is in the inverter.

    What you describe is consistent with an inverter IPM failure. The P0A94 is the trouble code I got when my IPM failed.

    The recall isn't one where you can take your car in and have the repair done as a preemptive measure. A vehicle has to have experienced the failure in order for the recall to cover it. Maybe that's why it's not coming up when you search your VIN. (I don't know.)
    According to the recall (linked below), it covers:
    Certain 2010-2014 Model Year Prius
    Certain 2012-2014 Model Year Prius V


    Here's a link to the JOV recall:
    https://attachments.priuschat.com/attachment-files/2018/12/158868_j0vtofaq.pdf

    You can download and print that, or just have it on your phone if you feel you might need it when you take your car in. But the dealer should know about it.

    Here's a link to a thread in which another member's Prius has similar symptoms as yours. I comment in that thread, and link to my own thread in which I outline my saga with a failed IPM, but with opposite symptoms (ICE wouldn't run, but electric propulsion still worked).
    3rd Gen Prius Inverter failure Toyota Reply | Page 2 | PriusChat

    The dealer needs to diagnose it. If it is the inverter IPM, it should be covered. You can call the dealer ahead of time and give them your VIN and ask them to see if your car is covered by the JOV recall.

    Good luck! Let us know how you make out.
     
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  8. PriusCamper

    PriusCamper Senior Member

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    I'm not as familiar with Gen3 than Gen2... And I have an inverter sitting on my shelf that I bought Summer before last because error codes in my Gen2 were pointing to a bad inverter and it turned out to be a loose cable in the battery pack.
     
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  9. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    I was under the impression that the inverter failure would cause my car not to start but now I see that's not the case. I was trying to diagnose the issue by ruling out or in problems others have diagnosed.

    OK I'm going to try my luck at the dealership, I'll call them again asking specifically about the JOV recall.

    Thanks for the details and advice, I will let you know how things go!!
     
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  10. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    That would be great thanks for sharing and my apologies I didn't realize that there would be significant differences between the Gen3 than Gen2.
     
  11. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    So just to update, I was able to take the car to the dealership and after a diagnosis they did determine that it was the inverter, long story short I got it repaired - details bellow.

    They told me that they can repair the inverter under customer support/care program for free BUT I had to update all my maintenance to be current first.

    They listed about 1.8k of maintenance... initially they wanted to do it all but after some conversations also said I can take it to another mechanic as long as I provide receipts of the work and historic receipts of maintenance preformed because their records didn't have a lot of historic maintenance.

    After checking the service manual and with our normal mechanic only the 90k maintenance was "required" and the rest was "recommended". I talked to the service manager who agreed that yes I only had to do the maintenance referenced in the manual and they can make it work by doing only the 90k maintenance.

    It was about $700 for the 90k maintenance but it meant that I can just drop my car off, get a rental, and then pick it up completely fixed without going back and forth and supplying receipts and digging for records.

    So now finally after a lot of time diagnosing, and reading, and negotiating the car is fixed and running without issue (so far at least).

    I think it would have been quicker, less haste, headache, stress, etc. if I just took it to the dealership right away and paid their price without thinking about it all, but I did save some money doing it this way, and now I'm more aware of the details to look out for and possibly some pitfalls as well.

    It restored my faith in working with dealerships, I got lucky to have a great service manager who worked with me.

    Thanks again for your help, appreciate it! Hopefully this detail can help someone too.
     
  12. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    Thanks again for your help! Ultimately I was able to get it repaired, details above, take care!
     
  13. tvpierce

    tvpierce Senior Member

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    Thanks for the update. I'm glad it worked out for you, but I would be looking for another dealer for future work. IMHO, their assertion is preposterous that you have to bring your vehicle's service up to date in order for them to correct this problem.
     
  14. HeyMikeyLikesIt

    HeyMikeyLikesIt New Member

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    Thanks I was wondering that too :/ My first instinct told me that there's something off with that, but I was tired of trying to get this done and busy with other things that I decided to just do it. I also called Toyota beforehand and was getting push back saying that my car was past warranty and my vin didn't have the recall, while the dealer was telling me they can get it done.