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Car died - battery, ICS, water pump, t-stat combo?

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by Carsten, Jul 3, 2023.

  1. Carsten

    Carsten Junior Member

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    I was driving, 2017 prius two, home yesterday afternoon in 100 F heat and suddenly got "ICS malfunction" message, there was another message too related to this, I think it was "crash detection system malfunction". Check engine light also came on and got a message to "pull over within 1/2 mile" and "take it to dealer". I did pull over and pop the hood, did notice the coolant was a little low so I added some, but nothing else glaring.

    I figured okay maybe it's just this ICS system, in which case I can probably make it home okay. Found someone online saying if you drive straight for 5 seconds >22mph the system will reset itself, tried that didn't reset.

    I drove for maybe a mile, same warning lights. Then I started to lose power and was barely able to get to an off ramp - uphill, at this time got a message something like "hybrid system failure". Coasted to a stop on the off ramp, turned off the car, sat for a minute, turned it on again and was able to drive then coast into a parking lot.

    Some of you are probably shaking your heads at my course of action... Oh well

    Got a $40 code reader from Autozone (why don't they rent the better ones?) and got P261B - water pump and P0128 - T-stat. I was really expecting more codes but maybe that's what you get out a $40 tool.

    Had the car towed home. The driver said he was sure it was the battery. Symptoms of battery failure don't really match tho.

    The only things that happened earlier in the day - got gas, ran compressed air into AC system to try to find a leak - I don't see how that could affect anything else, stopped at store - no sign of someone hitting it in the parking lot to mess up the sensors.

    Anyone have anything remotely like this happen? Could it be combination of dying battery and heat? And then there's water pump and t-stat codes?
     
  2. jerrymildred

    jerrymildred Senior Member

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    Ah, the old water laden air in the AC system ploy.

    Get a Prius literate code reader. I wouldn't be surprised if you get air conditioner and probably high voltage system codes from getting moisture in the compressor windings.

    The ICS messages are unrelated, but hopefully, you'll get info on those, too with a competent code reader.
     
    Doug McC likes this.
  3. bisco

    bisco cookie crumbler

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    if you listen to tow truck drivers, you'll end up driving one :cool:
     
  4. Carsten

    Carsten Junior Member

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    Got any recommendations?
     
  5. jerrymildred

    jerrymildred Senior Member

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    I won't restate what's already been discussed ad nauseam, but here's one of the countless good threads on the topic.
    Gen2 OBD2 app review | PriusChat

    My OBDII dongles include a Carista and an OBDLink LX, plus a very generic ELM 327 that I never use anymore. Apps are Hybrid Assistant with the OBDLink LX on an old Android phone. On my day to day iPhone, I have Carista, EngineLink, OBD Fusion, Dr. Prius, and Car Scanner. Each is better at some things than the others. Some require buying the specific Toyota PID codes from the vendor. I think it was about $10.

    If you really need to get serious, Techstream is the software Toyota uses. Pirated versions are available on Ebay, or to be legal, you can rent it from Toyota once you have the connector from the OBDII port to your Windows laptop. I don't recall the specific brand and name right now, but it should be easy to search for.
     
  6. Carsten

    Carsten Junior Member

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    Awesome, Thank you!
     
  7. M92

    M92 Junior Member

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    Just wondering, do you have any update on what happened? I just had a very similar experience and am not able to get to a dealer anytime soon.
     
  8. Carsten

    Carsten Junior Member

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    I'm just now back in SC, where my car is, so I haven't had a chance to do anything. I read through the thread that jerrymildred posted above and am about to order the thinkdiag OBD2 and app, hopefully I'll get that in a few days. At some point I'll post what I find out...
     
  9. Carsten

    Carsten Junior Member

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    I decided to get the Autel AP200 instead, it just seemed like it would be more reliable and the reviews on amazon are better. Finally got around to using yesterday. Turns out my 12v battery was dead too, took it to autozone and o'reillys to have it tested, a-zone said it tested "good" but wouldn't hold a charge (?), o'reillys said bad.

    The only code that came up, besides a bunch of old ones, was P261B - "coolant pump 'B' control circuit performance/stuck open" aka water pump. Then I found this on youtube, the first bit sounds pretty familiar. I think the combo of battery and water pump failure explains a lot, hopefully that's all it is


    I also found this, but couldn't track down an impeller for the gen 4


    I ordered a new pump and battery on rockauto, to be continued next week...
     
  10. Carsten

    Carsten Junior Member

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    Hey, it was totally the water pump, I'm sure the new battery helped too. Car runs better than ever.
    Replacing it really wasn't that hard either. What happened to yours?
     
    bisco likes this.
  11. Carsten

    Carsten Junior Member

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    Made this video
     
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  12. a2058

    a2058 Junior Member

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    Great video, that’s helpful! How many miles on your car when the pump failed? And how was the bolt stripped, that’s the bolt that goes at the motor mount, right? That’s M14x1.5 originally, is that right? Is it possible do you think, to get longer bolts there and hang the motor there as you lower the engine instead of leveraging with the piece of wood like you did in the video?
     
  13. Carsten

    Carsten Junior Member

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    Thanks! My first DIY video

    About 140k, I saw/heard somewhere that it's not uncommon for these pumps to fail after 100k. And I would dig deeper into just replacing the impeller, save $$$. There's some links in the notes on the video in case you didn't see them.

    I don't know how the bolt got stripped, it felt funny when I loosened it, you can see in the video it only turns a little and then it's free. I bought the car in April and do know that it was in a wreck bad enough to deploy the airbags. I suspect there was an engine swap at some point. Good thing they over-engineer things.

    The OEM bolts are M12 (probably x1.5). Without getting a flashlight and going out and popping the hood I think there is a block under the mount that is bolted on to the timing chain cover, I think. Haven't found a good diagram of this, maybe someday I'll get a service manual... Anyway, the bolt in question connects the mount to this block

    If I have to do this again, knock on wood, I will definitely try using the crowbar first as it really didn't seem like lowering the engine made any difference. I mean why not? So much less work and there's enough squish in the motor mounts. If you do need to lower it and want to try using longer bolts I would still put something between the engine and the frame so you don't damage the bolts seeing how the engine wants to tilt since the other mount is still holding it. Using longer bolts might make getting at other things tricky, like that guide bolt.
     
  14. a2058

    a2058 Junior Member

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    Thanks, that’s good info, as mine is also approaching that kind of mileage so thinking about preemptive maintenance soon on this. I will go grab a long crowbar from Harborfreight and give that a try!
     
  15. Carsten

    Carsten Junior Member

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    A sturdy piece of wood might do the trick, if you have one laying around give it a test pull. You only need a fraction of an inch.
    http://www.rockauto.com had the best price I could find. Aisin is the OEM brand.
    Lemme know how it goes