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Changed coolant control valve (P1121 fix) - CEL still on!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SRQ, Mar 9, 2013.

  1. SRQ

    SRQ Member

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    I disconnected the negative battery terminal for long enough to reset the ECU, but the CEL light came back on. The coolant control valve is new.

    My guess is that this is normal and the light will eventually go away on its own from what I remember reading on the subject.
     
    #1 SRQ, Mar 9, 2013
  2. jdenenberg

    jdenenberg EE Professor

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    Make sure that you have bled and completely filled the ICE coolant. It acts as a lubricant for the control valve and air bubbles in the loop can cause control valve to fail to actuate correctly.

    JeffD
     
    #2 jdenenberg, Mar 9, 2013
  3. SRQ

    SRQ Member

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    Wait, I replaced the coolant control valve and the inverter coolant only. I have not touched the ICE coolant. Could this be the problem?
     
    #3 SRQ, Mar 9, 2013
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, that is a big problem because the coolant control valve is part of the engine coolant loop.

    I have responded to another of your posts on this subject. It sounds like you could benefit from access to Toyota repair manual info, here: techinfo.toyota.com
     
    #4 Patrick Wong, Mar 9, 2013
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