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p1121, third replacement pump

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Gino Veltri, May 5, 2024.

  1. Gino Veltri

    Gino Veltri Member

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    ok i got a p1121 yet again. if i replace it again it’ll be my third pump. each one lasts shorter and shorter. it’s been like 3 months. Can the aftermarket parts really that bad?

    i’ve also got abs vsc and ! lights that go on but then they go off too, i’m thinking that’s metal particles on those abs sensor magnets. also got a code for MAF sensor underpowered the other day but that was a fluke (i’ll clean it anyway).

    i’ve bled the coolant until i no longer hear the sloshing liquid noise after start up. but i’ve noticed my heated coolant storage tank never really feels hot to the touch abd i couldve sworn it’s supposed to considering it stores heated coolant. right?
     
  2. PriusCamper

    PriusCamper Senior Member

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    That error code is for your three way coolant control valve... There's nothing wrong with your inverter pump.
     
  3. ChapmanF

    ChapmanF Senior Member

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    Can you tell us what part exactly you have replaced? PriusCamper assumed you meant the pump for the inverter, but then you are mentioning the CHRS tank, so it sounds like you might know this is the engine cooling system and not the inverter cooling system.

    The code you have, as PriusCamper mentioned, pertains to the three-way coolant valve in the engine cooling system. Is it possible that you've been replacing that valve, and you just wrote 'pump' in a hurry?

    As with most trouble codes, while there's a thing it chiefly pertains to (here, the coolant valve), there can be a few ways for an issue that isn't with the valve itself to trigger the code.

    The CHRS tank, by the way, is effectively a Thermos. It keeps hot coolant inside, and can keep it hot for more than a day—which means, by design, it had better not pass much of that heat to the outer wall where you could feel it.

    It's easy enough to get those trouble codes and post them here, and better than just trying to think what the problem might be. If you haven't got a scan tool that'll do it, you can get those codes like this:

    Blink (a/k/a Flash) Codes – How to. | PriusChat
     
  4. Gino Veltri

    Gino Veltri Member

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    of course i meant the valve when i said pump. three way valve i’ve replaced three times , i haven’t seen the code in some time and i keep an eye on the engine temp (never above 185). Could air just be stuck in the system or is there something else that could throw that code?
     
  5. Gino Veltri

    Gino Veltri Member

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    of course i meant the valve, not pump. the three way, i’ve replaced twice.
    good to know about the heated coolant storage tank, that seems normal. i totally forgot about blink codes! thanks for the reminder . i bet they’re the same one i got when i first got the car and had to replace the wheel bearings (what a pita that was!).
     
  6. Gino Veltri

    Gino Veltri Member

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    so my question remains what else could trigger the P1121 code if it’s not a faulty three-way valve. Clogging in the coolant system? Something along those lines?
     
  7. mr_guy_mann

    mr_guy_mann Senior Member

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    Yes, aftermarket parts can be absolute crap. I use parts from my local Toyota dealer and have had zero problems.

    That said, what have you actually TESTED? Does the CHS pump run after ICE shutdown and before startup the next morning? What does the ECT & CHS (water outlet) temperature read in the morning before and during pump operation?


    If you want to just throw parts at this problem you certainly can.

    Posted via the PriusChat mobile app.
     
    exstudent likes this.
  8. exstudent

    exstudent Senior Member

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    Assuming no rust/sediment in the cooling loops.
    1) Bad part since aftermarket.
    Who is the manufacture of this 3way valve? Where did you buy it from? If Amazon or eBay, just replace NOW w/ OEM. A lot of fakes on those sites.
    An OEM 3-way coolant control valve (16670-21010) would have been $110@Tustin Toyota online parts, $114@Longo Toyota online parts. You most likely have spent far more on parts so far, given two aftermarket part replacement. You probably have much better things to do with your limited time than to do repeat repairs due to poor quality parts.

    2) Air may still be in the system, preventing the valve from switching to the correct position for coolant to move to: CHRS, heater core, engine.

    Get Techstream. You can activate the CHRS pump, to help ensure all air is gone, as you re-bleed both loops (ICE & Inverter).
     
    #8 exstudent, May 24, 2024
    Last edited: May 24, 2024
  9. Gino Veltri

    Gino Veltri Member

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    this is the way, i’m sure. the last time i got techstream up and running, it took me so long to install it properly that i’d fixed my issues by the time it started. then i realized operating techstream is just as complicated as getting it to work. then someone stole that old windows laptop out of the car so techstream is a pipe dream for me. personally, the 2nd gen prius is as technologically advanced as i get.