P1121 Fail fix

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PrestonH2O, Aug 10, 2025 at 2:05 PM.

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  1. PrestonH2O

    PrestonH2O New Member

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    2007 Prius
    Model:
    II
    I tried to fix my p1121 error code by replacing the 3-way coolant control valve. I even got OEM.

    I ended up spilling all the coolant on the ground. I also had to take one of the hoses off the coolant pump which I then forgot to put back on when I started the car. I then put it back on once I realized my mistake. I have refilled, and possibly overfilled the coolant system but the coolant doesn't seem to be circulating. The coolant system also seems to be making a weird noise like it is trying to pump and getting nothing? Could there be air in the system?

    I am having the following error codes now:

    P0117
    P1121 - still, even after clearing code
    P0A0D - I triple checked the service plug and I am pretty sure its all the way in and pushed down! The red triangle goes on and off.

    Any idea what the problem could be? Did I break the pump or put air in the system?
     
    #1 PrestonH2O, Aug 10, 2025 at 2:05 PM
  2. PrestonH2O

    PrestonH2O New Member

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    2007 Prius
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    Update: I am now ONLY getting P0A93. Also at one point all the lights on the dash went on including the E-break light and it started beeping really loud but that stopped and hasn't happened again.
     
    #2 PrestonH2O, Aug 10, 2025 at 3:16 PM
  3. Tombukt2

    Tombukt2 Senior Member

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    Take rad cap off . If coolant is not sitting at top of neck you is not full now pour a stream of red in neck . Sloooowly. When you finally get it to stand at the top of the neck for 5 minutes you're full that's going to take you 40 minutes and a quart or better of coolant let me know you gonna be pouring 20 35 min . It goes slow . Obviously make sure all hoses are on and clamped not hanging
     
    #3 Tombukt2, Aug 10, 2025 at 7:01 PM
  4. dolj

    dolj Senior Member

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    By chance, did you unplug the inverter coolant pump and overlook reconnecting it?

    Prius Gen II Inverter 1 Pump.jpg
     
    #4 dolj, Aug 11, 2025 at 5:03 AM
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