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The Red Triangle was only the beginning

Discussion in 'Gen 2 Prius Main Forum' started by Joseph_G, Dec 31, 2021.

  1. Joseph_G

    Joseph_G New Member

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    2005 Prius
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    ----USA----
    A little over a week ago my car started beeping fairly infrequently and showing the red triangle with an exclamation point in it at times when I was braking. A quick call to my mechanic revealed that it could be a problem with the hybrid battery but if the battery failed the car would just become a traditional gas car.

    That was fine for the time being and I scheduled a visit (since I needed my 140k service anyway) for the day after I get back to Northern California. That would've been fine if the car didn't expand to then show all the symbols in the attached photo.

    Still, the car drove even if the mileage was deteriorating, the hybrid battery would always start out with only one or two bars and it had a tendency to lurch when driving. Yesterday it started blowing air loudly out of the battery vent near the back right seat, which was annoying but seemingly par for the course for hybrid battery issues. However today about half a mile from where I was staying, the car stopped being able to accelerate past 25 mph no matter how hard I gassed it. After stopping for about half an hour and checking for some common problems I drove the car around the block and it appeared to be able to accelerate properly again.

    Any advice on what I should do next? I no longer trust the car to drive back home to my trusted mechanics
     

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  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!
    When was the last time you checked the engine oil?
    It sounds like you have a failing HV battery. Next step would be to make a plan to either fix it yourself, or pay someone else to do it for you. After making a plan, you should visit each of the auto parts stores (even within the same chain) and get a free OBD2 scan. Once you know, and have recorded the OBD2 codes (DTCs), post them here for additional guidance. Which part of Norcal/Socal are you currently near?

    FYI : you're moderated until you've posted 5 times.
     
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  3. jerrymildred

    jerrymildred Senior Member

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    It's very possible that the traction battery has a problem. As @SFO pointed out, you need to get the codes read. Make sure they use a scanner that's sophisticated enough to talk to all the ECUs in a Prius. Most are not.

    But I'm not sure the battery actually has a problem if the warning light is just coming on when you brake and then goes back off. That's the car screaming at you to check the oil and top it off. But it may be too late for that and the damage is already done. Not going over 25 mph and the battery fan running loudly suggests that the electric motor is trying to compensate for a partly seized engine. On the other hand, if it's original, that's a pretty old battery and it's already performed beyond the typical lifespan.
     
  4. Another

    Another Senior Member

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  5. ChapmanF

    ChapmanF Senior Member

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    I second the recommendation to get the trouble codes read.

    Additionally ...

    ... I would avoid going back to that mechanic with Prius questions.

    When the traction battery fails, a Prius will not "become a traditional gas car." It will become stationary.

    That's a fairly basic thing for a mechanic to know about the car.
     
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  6. pasadena_commut

    pasadena_commut Senior Member

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    For whatever it is worth, that mechanic's description isn't strictly correct for Honda Civic hybrids either. Yes, there is an auxiliary motor starter, so the gas motor can be started without the electric motor if the IMA is dead, but under many driving conditions nothing is charging the 12V, and it is possible to run the 12V down to the point the car stops. So while the HCH "sort of works" without the IMA, it is definitely not like a "traditional gas car". The closest analogy would be a gas car with a failing alternator, and who wants to drive that?
     
  7. Joseph_G

    Joseph_G New Member

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    Hi everybody,

    Thanks for all your input. I checked the oil and the level and color appear fine. I've a scheduled oil change/140k service next week so assuming I can drive back up (from LA where I currently am visiting family, back to East Bay where I live). The car does also seem to run better when the Heat is not on and has not had the same issue when I drove it today. I went to Autozone and had an OBD2 scan. As @jerrymildred mentioned their scanner was not sophisticated enough to communicate with all the ECUs. I got C1259 and C1310 plus a secondary DTC C2318 which based on what I've read thus far in the forums is not actually all that helpful.

    I did (at the behest of a Prius owning family member) test out the regular 12V battery. The voltage when the engine was off was below 12V (It was 14.3V when the engine was on) and would go down closer to 11V if the headlights were on. When I asked AAA to double check they said the 12V battery was failing some of the standard tests. Is it possible that that could be at least partially responsible for the issues?

    For context the hybrid battery was never changed, the 12V battery was changed 7-8 years ago.

    Thank you all for the help. I appreciate the input!
     
  8. SFO

    SFO Senior Member

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    Highly unlikely. Replacing the ancient 12v may be a good idea, but only after you've sorted out the HV battery issue.
    Both of the above (HV battery fan running on high, and 25 mph "turtle mode") are symptoms of a failing HV battery, if you plan on driving 350+ miles north in the current degraded state, you should drive slower, and don't stress the HV battery by braking or accelerating quickly. Think about taking the 101 instead of the I-5, as the grapevine may be too much for the HV battery to handle.

    Do you (or someone you know) have basic tools and a DIY attitude, or will you be paying to repair/replace the HV battery?
     
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  9. Joseph_G

    Joseph_G New Member

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    @SFO Thanks for the advice. I was already planning to take the 101 as it is slower, safer, and easier to get towed to a city from.

    I would likely pay to repair/replace it (though if there wasn't such a backlog on cars I would consider just buying a new car). My DIY attitude falls off after the basic car emergency things (jumping a battery or changing a tire)
     
  10. ChapmanF

    ChapmanF Senior Member

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    The first two are helpful in a well-now-you-know-for-sure sort of way. C1259 and C1310 are codes the brake ECU sets to tell you that it has been alerted to codes in the hybrid vehicle ECU.

    So now, if the scan tool you are using is not showing you codes from the hybrid vehicle ECU, you know for sure you need a better scan tool to retrieve the codes you now know are there.
     
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  11. Joseph_G

    Joseph_G New Member

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    Hi all,

    I just wanted to update you guys with the new codes and my journey thus far. Piecemeal, I was able to make it back to Northern California. To @jerrymildred and @Another 's points, the car complained less when I topped off the oil (it appeared to have gotten lower since I last checked which means my engine is burning oil), but the turtle mode would still occur even after that.

    The full slate of codes included:
    P0A80-264
    P3000-123
    P3018
    P3019
    C1259
    C1310

    So the HV battery is the issue. Given how expensive new and used cars are right now, I will now work (likely pay for someone else) to fix the battery and get back to driving without worries.

    Thank you for your help :)
     
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  12. SFO

    SFO Senior Member

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    Unlikely that anyone would recommend buying a 'reconditioned' or 'refurbished' HV battery, which is another way of saying "used". Most of the $350-$1500+ HV battery swap services won't last any length of time and you will be right back where you started from. Many here will recommend a NEW oem battery from the dealer (around $1800 with self install), or one of the NEW batteries linked below :

    $1990+tax+delivery for a NEW lithium replacement : https://Projectlithium.com/

    $1600 total, which includes delivery for a new NiMH replacement : NewPriusBatteries.com | Home

    Let me know if you need any assistance with the install, as I'm just across the bridge.

    Have you (or your mechanic) ruled out swapping the failed modules and "balancing" the existing pack?
     
    #12 SFO, Jan 10, 2022
    Last edited: Jan 10, 2022
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