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Water Valve/coolant control valve

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by vegliare, Dec 5, 2018.

  1. vegliare

    vegliare Junior Member

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    Hey all,

    Moms 2008 has a P1121 code that reads as coolant control valve. Shop wants $400 parts/labor. I figured I would just do it myself then replace other needs at the same time.

    My question is at her mileage of about 110k, should I look at also replacing things like coolant temp sender, water pump, etc.

    Thanks for your input.
     
    #1 vegliare, Dec 5, 2018
  2. JC91006

    JC91006 Senior Member

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    Some states that have emissions warranty for 15 years/150k miles, so make sure you are not in those covered states before you start messing with it. It could be free
     
    #2 JC91006, Dec 5, 2018
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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I would suggest you look at the engine coolant pump and replace it if there is any sign of coolant weeping at the bearing. Maybe replace the engine thermostat. Definitely replace the serpentine belt.

    I have not seen any reports of a failed coolant temperature sensor so that would be low on my list of items to worry about.

    Are you aware of the need to purge air out of the coolant heat recovery system loop? If you are not aware of that requirement, please see my posts #22 and #42 in the following thread plus the surrounding discussion.
    Changing engine coolant | Page 2 | PriusChat

    The two main thoughts to keep in mind are: 1) keep track of the amount of drained coolant as you know you are not done until you've added at least that amount back into the system and 2) you need to run the CHRS pump either by using Toyota Techstream via software control, or by manually bypassing the CHS relay as my post explains.
     
    #3 Patrick Wong, Dec 5, 2018
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  4. vegliare

    vegliare Junior Member

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    Thanks all. And sadly Florida is a bad example in regard to emission regulations, as in they basically don’t exist.
     
    #4 vegliare, Dec 5, 2018
  5. edthefox5

    edthefox5 Senior Member

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    Hey Pat is there a write up on replacing that valve mine is starting to get cranky thanks.

    Ray
     
    #5 edthefox5, Dec 6, 2018
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Ray,

    I have not had to change that valve but I believe others have written about that.
     
    #6 Patrick Wong, Dec 6, 2018
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