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P1121 code - what all do I need to do?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ProblematicPrius, Jul 24, 2020.

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  1. ProblematicPrius

    ProblematicPrius New Member

    Joined:
    Jul 24, 2020
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    Location:
    Hartford, CT
    Vehicle:
    2006 Prius
    Model:
    Two
    My 2006 (153k miles) came up with a CEL on my way home last night, plugged in my OBD2 and got P1121. I've researched around a bit, watched some videos, and I feel pretty confident about replacing the coolant control valve myself. However, I've seen some conflicting information about what's necessary for this repair. Do I also need to drain and refill the coolant, then bleed the air? Is this necessary, or can I get away with just replacing the valve without replacing the coolant? Or are there other steps that need to be taken too? I want to do it right the first time, so any insight on what's the best process for resolving this issue would be helpful. Thanks!
     
    #1 ProblematicPrius, Jul 24, 2020
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,470
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    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    This is a good opportunity at 153k miles to change out your coolant. It will leak everywhere when you do it (unless you clamp the hoses), it'll just be easier to let everything drain and then put new coolant in when you're done.
     
    #2 JC91006, Jul 24, 2020
    Raytheeagle likes this.
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