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P1121 - Coolant Control Valve Replacement (with pics)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Stomper88, Jan 24, 2012.

  1. hchu1

    hchu1 Active Member

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    Anything is possible, but not likely. I will likely replace one on my '06 with 157k miles this weekend. I've put it off for the last 8 months, time to make it right.
     
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  2. Frank Kasell

    Frank Kasell Junior Member

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    That sounds almost identical to mine. 2006...157k miles. Crazy. So, this thing is okay to drive around with for a while? I'm not facing critical engine failure?
     
  3. hchu1

    hchu1 Active Member

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    Yep, non-critical for operations, will give you time to decide how you want to go about fixing it, diy or paid route.

    You will notice that the check engine light will go out after a while and will come back on. That is the only issue, to me, for not getting it taken care of immediately. You won't know if the check engine light is on for another issue unless you have a vci with techstream to read what set it off everytime it comes back on.
     
  4. andrewclaus

    andrewclaus Active Member

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    P1121 is a common code, and not connected at all to an oil change.

    It would be a good idea to check your coolant level at the neck of the (cold) radiator, not just at the overflow reservoir. You have to remove some pesky fasteners for access.

    Who read the codes? If they did not use Toyota's software, some may not have been read.
     
  5. Frank Kasell

    Frank Kasell Junior Member

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    Thanks, Andrew. Where would I find the neck of the radiator? I checked the reservoir the other day and it looked fine, but I'll gladly check the other spot as well.

    The codes were read at an auto parts store, so it's possible they missed something I suppose.
     
  6. andrewclaus

    andrewclaus Active Member

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    You have to remove six fasteners in the black splash shield right behind the grille on top of the radiator. The fasteners are removed by turning 1/4 turn then prying up, but they can also be pushed up from below with your index finger. Do not open a hot radiator! Coolant level should be to the top of the neck, right up to the cap. Next time you do it, you can try just removing the right-most two fasteners.

    It's remotely possible the oil change caused a coolant leak and you should check that right away.
     
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  7. Jmack111

    Jmack111 Member

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    Remove front bumper and driver headlights 3 bolt and 3 hose on pump just change fast and add coolent to radiator the one on top of radiator under cover

    Posted via the PriusChat mobile app.
     
  8. Frank Kasell

    Frank Kasell Junior Member

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    Thanks, all! One other question: we noticed today that the heat is taking a long time (like 45 minutes) to heat up. Until then it was all cold air. Could that be a related problem? Thanks again.
     
  9. andrewclaus

    andrewclaus Active Member

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    Yes, a failing three way control valve may affect cabin heat in some modes.
     
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  10. geeman

    geeman geeman

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    I had the dealer replace the three way. Then less than 50 miles later the temperature sensor needed replace. I suspect that they broke it getting the three way back in. Question is my assumption possible? Thank you
     
  11. Travon Bryant

    Travon Bryant Junior Member

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    Hello so i have recently replaced my coolant control valve (one day ago) all hoses snugged on. No leaks. I also went as far as clearing out all the old coolant.

    But my engine check light has not gone off. It left and then when i began to run the ac it came back on. Code still reads p1121, when the new coolant control valve was placed on i did hear a small buzz. But that has sense gone away.

    Whats happening here?
     
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You still have air in the engine coolant loop, most likely. What was your process to get air out of the system after changing the valve? How well does the cabin heater work?
     
  13. Travon Bryant

    Travon Bryant Junior Member

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    I performed a radiator fluid exchange they took all the fluids out and got the air bubbles out. My ac and heater inside the car works well. Gets hot and cold nicely.

    The buzzing i noticed is only when its idling. I feel fluids passing through the hoses.
     
  14. Travon Bryant

    Travon Bryant Junior Member

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    Also say i do have air in the engine coolant loop. How do i go about getting the air out
     
  15. Jmack111

    Jmack111 Member

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    You fill all 3 spot including the radiator after running it

    Posted via the PriusChat mobile app.
     
  16. Travon Bryant

    Travon Bryant Junior Member

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    Yes. All three filled back up to the fill line.
     
  17. Travon Bryant

    Travon Bryant Junior Member

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  18. notacarguy

    notacarguy New Member

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    A couple months back I used this tread to replace my coolant control valve worked like a champ. All was well... Fast forward to yesterday my wife was driving and the big red ! came on. First thing I checked was the control valve thinking I didn't tighten clamp or something. hoses are fine but the plug at the top of the control valve was not there. Assuming this was not suppose to be that way I purchased another control valve and that plug is not permanently a fixed either! So I placed the plug back in (loosely fitting) with low hopes of it working, Yup did not work. Has anyone else had this issue or similar? I'm at a loss any input would be appreciated.
     
  19. Avi's Advanced Automotive

    Avi's Advanced Automotive Independent hybrid repair shop

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    Let me guess, aftermarket part...

    Posted via the PriusChat mobile app.
     
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  20. notacarguy

    notacarguy New Member

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    Yes, Advance auto finest