Stutters at Specific Point on Hybrid System Indicator

Discussion in 'Gen 3 Prius Technical Discussion' started by msenkpiel, Jul 30, 2019.

  1. msenkpiel

    msenkpiel New Member

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    2011 Prius Gen 3, 270,000 miles stutters and gets jerky 3-5 bars into the power side of the Hybrid System Indicator ECO mode (See attached photo). Everything else seems normal, e.g. idle, acceleration, etc. It is consistently and reliably shaky at that point on the HSI whether on the highway or in the city. There are no error codes, no check engine light, no scary exclamation triangle.

    Things that have already been done (by Toyota Service or myself) trying to solve the issue: New spark plugs, new coils, cleaned fuel injectors, cleaned MAF sensor, cleaned intake manifold, cleaned EGR pipes and cooler (made that damn cooler look brand new!), and replaced head gasket. Whew. The timing chain and sprockets looked pristine, and the links lined up exactly, so I didn't replace them.

    Things that were done just because they needed doing: new brakes, turned rotors, new inverter coolant, engine coolant, and oil.

    Any ideas are greatly appreciated. Could it be the transmission?

    HSI.jpg
     
  2. PriusCamper

    PriusCamper Senior Member

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    In older high mileage battery packs I've experienced the symptoms that you've described... Have you noticed your hybrid battery charge dropping faster than it used to? If so I suspect your hybrid battery is losing capacity and needs a few rounds of deep/cycling (reconditioning) as well as a full charge and balance between each deep cycling effort to fix the problem.

    If you know how to do your own work on your car, installing the $150 charging harness is easy, but the high voltage trickle charger is a bit expensive, so maybe you can find someone on PriusChat that lives near you who has one you can periodically borrow/rent? Learn all about it here:

    FAQ

    and here:

    BU-807: How to Restore Nickel-based Batteries – Battery University
     
  3. msenkpiel

    msenkpiel New Member

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    Wow, I would have never imagined that! Now that you mention it though, since I started it after the head gasket change (it was down for 3 weeks because I could only work on it a few hours here and there), the battery packs went down to 2 bars a few times (which I've rarely seen) and then completely full (which I've never seen), then back down again. It always recovers, so I assumed it was because of being down so long. Thanks for the suggestion. I'll look into that.
     
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  4. Raytheeagle

    Raytheeagle Senior Member

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    Welcome to Prius Chat (y).

    Sounds like you’ve done a bunch of work to your 2011:).

    When has the trans fluid been changed:whistle:?

    How long ago did you do all of this work?

    Good luck and keep us posted (y).
     
  5. msenkpiel

    msenkpiel New Member

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    I'm not sure about that. Started to google how to check the trans fluid level yesterday, but got side tracked. Toyota may have changed it at some point when I had a service contract, but I never paid much attention then because this car never had a single issue until about 6 months ago! That's when the shaking started. All those things have been done since then, the head gasket just last week. I'll check the trans fluid level. Maybe I can check with the Toyota folks to see if they have a record of the last change, if any. But probably can't hurt to change it anyway if in doubt. Thanks for the suggestion!

    PS - the battery indicator dropped suddenly from almost full to 2 bars again today. It charges back up eventually, but this is definitely new behavior.
     
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  6. PriusCamper

    PriusCamper Senior Member

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    Toyota has no service schedule for changing trans fluid and says fluid is good for life of the car... But the fact is the first 1000 miles of any new engine or transmission is going to get contaminated with micro-metal particles that shed as all the parts wear into their function, so change it to decrease long-term wear.

    Also in your first post you said the car stutters and gets jerky at a specific hybrid battery charge level... But then in your most recent post you referred to the symptom as "shaking" which sounds more like an engine problem, than a battery problem.
     
  7. msenkpiel

    msenkpiel New Member

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    I would say stutter, jerky, and shaky all describe the effect. It definitely seems mechanical to me, but maybe that's just my ignorance that I can't fathom how the hybrid battery could make it do any of those things while all indicators appear normal. BTW, I want to clarify - it happens at a specific Hybrid System Indicator level, not the battery charge level. The battery charge is unchanged during the episodes. On the Energy Monitor screen, the ICE, EM, and battery charge indicator all appear unchanged during the episodes, i.e. it's not when the ICE is turning on or off (or a change in charging the generator or battery pack), and it's not when the EM is turning on or off. All of these things do not consistently change during an episode.

    The only thing other than the HSI indicator that is consistent is that the MPG indicator is always at 75, but that's what made me look at the HSI - those two things correlate and it seems unlikely that a specific MPG could have anything to do with it. In my mind, the HSI thing seems like it could be a bad spot in the continuously variable transmission. If a CVT is anything like a PIV, this seems possible to me. (PIV = Positive Infinitely Variable - I used to work on these at a textiles mill back in the day.)

    Anyway, so 80% of my miles are highway, but it also does it in the city (at the exact same spot on the HSI). I noticed yesterday that in the city with the windows down, I can also hear a flapping or knocking sound during the episodes. It sounds like it's coming from under the hood on the driver's side, but that's kinda what my ear is closest to.

    Regarding the batter indicator, since forever, it's almost always at 2 bars down from full. The only time I have noticed it unusual is this week, after it had been sitting for 3 weeks. It went quickly from 2 bars down to almost empty twice when I first drove it on Saturday, and then once yesterday. And it went suddenly completely full somewhere in there also. So it does seem that - and is due for my battery pack to need reconditioning or changing. My MPG is down to about 43 now too.

    I'm just trying to make my Prius last til my daughter gets out of college so I can get a Tesla. :D

    Thanks for all the help!
     
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  8. PriusCamper

    PriusCamper Senior Member

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    Well, it's starting to sound like an overall power performance issue and you're gonna have to wait for whatever is wrong to get worse to figure out what to do next. I'm a gen2 person so I don't have much experience with Gen3 display. I thought eco-mode was something you could turn on or turn off? Does this problem not happen when it's not in ECO mode?
     
  9. msenkpiel

    msenkpiel New Member

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    It's not in eco-mode. I'm just referring to the name that is above the scale in the display. The scale says ECO above it. I don't have a technical understanding of what the display means, only a practical understanding from observation that when I coast, the indicator goes to the left, into the "CHG" range and if I apply braking, it goes further into the "CHG" range. During acceleration, the indicator goes into the range under the word "ECO" (and into "PWR" if extreme enough). The scale under the word "ECO" is divided in half - the left half on the charge side, and the right half on the "PWR" side. Always, at the same place (indicated by the red arrow in the photo) the car gets stuttery and if I accelerate or coast such that the indicator moves from the "bad" spot, the stuttering goes away and the car performs as expected.

    [​IMG]
     
  10. RMB

    RMB Senior Member

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    You said it is consistent shaking at those particular bars on the HSI, it would lead us toward engine drivability issue since this is happening at a certain engine speed, 1200-1500 rpm, maybe.

    Now that you’ve mentioned you or someone did all of the cleaning and replacement including the head gasket, have you also looked into fuel pressure (perhaps a bad fuel pump?), the gasoline that you use (maybe bad quality gas and the gas turned worse when your car sat for 3 weeks?), and maybe, just maybe, EGR System wasn’t really cleaned very well or EGR valve went bad at a certain time since the cleaning?
     
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  11. cnc97

    cnc97 Senior Member

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    Since it’s the same point every time, I’d look at the trans mounts, or the engine mount. As the ICE spins up first, then gets ignition, then injection. It’s possible that you may have a fuel issue, but I believe that you have a bad mount. The “vibration” as the ICE starts could be interpreted as a shudder.
     
  12. PriusCamper

    PriusCamper Senior Member

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    Thanks for clarifying... At this point I'm fairly certain everyone's responses have likely identified what's wrong, it's just a matter of figuring out which one is the right one.

    Your car generates huge amounts of sensor data and the more you can view the data when this problem occurs the more likely you'll identify the problem. The easiest way to establish that would be to use the hybrid assistant app with it's companion app hybrid reporter.

    Once you have that all set up, take it for a short test drive and try to make the problem happen as often as possible. Then when you get done with the test drive, even if it's just a few miles, Hybrid assistant app will give you 10+ pages of charts and graphs of sensor data and hopefully you'll be able to zoom in on where the problem is coming from... Perhaps you could even upload that data to this thread so we can look through it as well and help you find the problem?
     
  13. msenkpiel

    msenkpiel New Member

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    Ahhhhh...This is exactly what I've been needing! Not sure how I missed its existence. Thanks so much - I'm on it!
     
  14. PriusCamper

    PriusCamper Senior Member

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    Fairly sure this function was exclusive to Gen2 Prius... Your 2011 Prius is set up differently.
     
  15. Rayman2010

    Rayman2010 Junior Member

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    My 2010 stutters like that for a second or two after I make a fast hard left or right turn......can't figure it out

    Posted via the PriusChat mobile app.
     
  16. AzWxGuy

    AzWxGuy Weather Guy

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    I would guess funk in the fuel tank encountering the fuel filter when set in motion by the "hard" maneuver and momentarily restricting fuel flow. Just a guess but probably not. More likely it is funk in the intake manifold getting aspirated during the maneuver.
     
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  17. cnc97

    cnc97 Senior Member

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    I came here specifically to add this remark.
     
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  18. PriusCamper

    PriusCamper Senior Member

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    Gen2 Prius have similar problems as a type of latency that gets increasingly worse depending on how old and in need of reconditioning the hybrid battery is, as well as an over-active traction control system. Toyota mostly addressed these issue in Gen3, but they can still be a bit problematic in some cases...
     
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