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Coolant Control Valve (P1121/P1123) Issues

Discussion in 'Gen 2 Prius Technical Discussion' started by Jonnynov, Feb 21, 2020.

  1. Jonnynov

    Jonnynov New Member

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    So im new to the prius world, i bought a 2007 at an auction recently. It had a check engine light on it. So we scanned it and it came up with the P1121 code. We reset the code and drove it for 15 miles or so and the light came back on. So we decided to put a new coolant control valve in. After installing the new valve, we reset the codes and turned the car back on. The check engine light came back on immediately and it threw a new code, a P1123 code. We tried to reset it, but it wont let us clear the code. So we plugged the old valve back and the code was gone, drove for 30 miles and the P1121 code came back with the old valve installed. So im looking for help as to why when we put the new valve in, is it throwing a code that says the voltage is too high and when we put the old valve in, that code goes away but says the valve is bad. Thanks for any help, we are at a complete stand still with this thing.
     
    #1 Jonnynov, Feb 21, 2020
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Here is the workup for DTC P1121 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/2054m/cip1121a.pdf

    Here is the workup for DTC P1123 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/2054m/cip1120a.pdf
     
    #2 SFO, Feb 22, 2020
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  3. Tideland Prius

    Tideland Prius Moderator of the North
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    @SFO , are the links legit? some of our antivirus software is flagging this.
     
    #3 Tideland Prius, Feb 22, 2020
  4. SFO

    SFO Senior Member

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    PDFs are one of many file types that can be pay loaded, and I have yet to cross such a PDF in years of viewing/downloading. Not to say that I could even identify or remove the payload from a PDF that has any decent spy/gov level rootkit using the consumer level tools available. Wouldn't surprise me if my machine has been rooted for years :cautious:

    Just ran a virustotal on one of the above PDF links, and here are the clean(?) results : VirusTotal

    Curious what antivirus product the website/server is using, as I've never had a drive-by issue with that website. Sometimes I will get false positives from google for other websites, but generally just ignore them and continue surfing to my destination. But my machine is locked down enough that I don't worry about infections and such.

    That website and the many gen2 links have been shared and used here on PC for years, pretty sure I initially found a link to that website when searching on PC, and standalone links for that share.qclt.com domain still show up in search results from many of the search engines. Sometimes the GFWoC causes access issues to many/all of their links, but it could just be the PRC host acting up.

    Just to clarify, malwarebytes and spybot s&d fail to flag it as suspicious when surfing with my browser to any of the links posted.
     
    #4 SFO, Feb 22, 2020
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  5. Tideland Prius

    Tideland Prius Moderator of the North
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    Ok thanks! I got a report so I’d like to get more eyes on it.
     
    #5 Tideland Prius, Feb 22, 2020
  6. Jonnynov

    Jonnynov New Member

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    Well, update on whats going on with the car now. We bought another new coolant control valve on the off chance that the one we purchased that was throwing the p1123 code was actually bad. We installed that one and a new code came up. P1122, which is low voltage to the control valve. and it wouldnt let us reset the code at all. So i gave up, i brought it to the dealer and told them to do what they had to do to fix and let me know. They called me back two days later and said they had fixed it and there was no charge because the coolant control valve they had replaced in november was faulty. I thought i was golden, till i drove it out of the parking lot and the engine light came on. Apparently the tech had driven it with the engine already warm and the light never came back on, it comes when when the engine gets cold and has to warm up. So they said they would look further into. I got a call a couple days later telling me that it must be something in the wiring, and that a new harness would cost $4000 and the labor to install it would be an additional $1500. So i think im going to have to retire the car and parts it out unless some has a better suggestion or knows anyone that wants to work on the wiring, because no one i know wants to jump into that. Thanks again for the help, we almost had it!
     
    #6 Jonnynov, Mar 8, 2020
  7. SFO

    SFO Senior Member

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    #7 SFO, Mar 8, 2020
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  8. Thomas Wesley Heard

    Thomas Wesley Heard Junior Member

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    I think I’m in the same boat. Just replaced my coolant valve and checked the wiring. The p1123 code is still popping up. Took it by my local mechanic and he did what he could do. I’m gonna take it by the dealer but it may cost more than the car. Any thoughts?
     
    #8 Thomas Wesley Heard, Apr 28, 2020
  9. SFO

    SFO Senior Member

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    Did you print out the DTC P1123 workup for the local mechanic to go step by step?
     
    #9 SFO, Apr 28, 2020
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  10. dolj

    dolj Senior Member

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    Did you check the integrity of the wiring and connector(s)?
     
    #10 dolj, Apr 29, 2020
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  11. 05PreeUs

    05PreeUs Senior Member

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    I am going to go out on a limb here and GUESS that the CCVs purchased were not obtained from an Authorized Toyota Dealer and therefore not "OEM" parts?

    Did the limb break? Bet not.
     
    #11 05PreeUs, Apr 29, 2020
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  12. Inquisitive Dan

    Inquisitive Dan Junior Member

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    II
    I was also getting P1123 intermittently and noticed the coolant was low as part of my check so I added some. I had my father in law who is a very experienced mechanic replace the coolant control valve 9 months previous when my 2004 prius with about 250 K miles was throwing solid P1121 codes.

    I really appreciated this thread, especially SFO giving us the workup. I am pretty inexperienced as even a home mechanic but this thread made me dig in a bit more and measure the relevant ECM connector voltages and resistances behind the glove box. It took me a long time to do this fairly simple task but I learned things like using t pins from staples to probe the back of the connectors and how important it is to have a good manual.

    So I watch the voltages as I drove and I saw they were erratic. Finally I got a smoking gun when I found a drip of coolant under my car. Took the car to my local mechanic and he showed me on the lift that the 9 month old after market coolant control valve was leaking. Including picture below.

    Got an original toyota coolant control valve and we replaced the 9 month old after market valve with the new one which fixed the problem. Then I read amazon reviews for after market part and found many similar stories. Hoping this one lasts longer then 9 months and lesson learned. Thanks for the great info in pruischat and the helpful spirit.
    Screenshot_20200429-142152.png
     
    #12 Inquisitive Dan, Apr 29, 2020
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  13. 05PreeUs

    05PreeUs Senior Member

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    Yea, I do not advocate for, nor use myself, aftermarket electrical components.
     
    #13 05PreeUs, Apr 30, 2020
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