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P1121: Prius Coolant Inverter Pump after fixing Coolant Control Valve

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Symanx00, Nov 17, 2022.

  1. Symanx00

    Symanx00 New Member

    Joined:
    Nov 17, 2022
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    Location:
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    Vehicle:
    2008 Prius
    Model:
    Two
    Hey friends,

    I have a 2008 Prius with about 107K miles on it. I have had my check engine light come on with P1121 code. I have been leaking coolant consistently for a week or so now. I had the Coolant Control Valve replaced about 3 months ago and the Coolant Inverter Water Pump replaced about 2 years ago (OEM). I took the vehicle to my mechanic and he told me that the water pump was broken. However, I am not seeing a code for any issue with the water pump as I did a couple of years ago. I am only seeing the P1121 code that says there is something wrong with the coolant control valve I just had replaced in August. Seeing if anyone has had a similar experience, and if so, what do you recommend.

    Simon
     
    #1 Symanx00, Nov 17, 2022
  2. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
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    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    Any coolant pump can leak- that has nothing to do with any codes (at least until the system gets too low and something overheats). Which pump is it? Belt driven engine pump? Inverter pump? Heater pump? Coolant heat tank pump?

    90 + percent of the time, a P1121 is the result of a fault in the coolant control valve. There's a slight possibility that the connector or wiring is bad, or something in the system is restricted. I think there has been a case where two hoses on the valve were incorrectly swapped.

    What brand of valve was installed? In general I only recommend OE Toyota from a reputable source. Aftermarket parts can/have caused too many problems for me to consider using them for things like this

    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, Nov 17, 2022
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