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Replaced Coolant inverter p2601 but still showing check engine

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Prius4lifer, Oct 25, 2021.

  1. Prius4lifer

    Prius4lifer New Member

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    I have replaced my 2006 coolant inverter with an oem one from Toyota dealership after it went out. After I replaced the car is running great. I can hear the inverter running and seeing the inverter coolant reservoir spinning. I also did a bleed on the system. But after a hundred or so miles the check engine would come back up with p2601. But I have check the coolant reservoir and I can see the liquid in there moving, also heard the inverter working. I also did another bleed and checked the wires which looks like its all in working condition. I am not sure whats going on, everything I do a reset it comes back. My car is also getting a lot better gas milage after this was replaced. Any idea what is going on? Should I reach out to toyota for a inverter replacment?
     
    #1 Prius4lifer, Oct 25, 2021
  2. SFO

    SFO Senior Member

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    #2 SFO, Oct 26, 2021
  3. ChapmanF

    ChapmanF Senior Member

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    In case of any confusion, the "CHS" water pump referred to by P2601 is part of the engine's cooling system, and nothing to do with the inverter's cooling system.
     
    #3 ChapmanF, Oct 26, 2021
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    As mentioned, the code you have is not related to the inverter coolant pump. Your car has four coolant pumps- one (electric) in the inverter cooling system and three in the Internal Combustion Engine cooling system (a mechanical pump driven by the belt on the crank pulley, an electric pump for the heater, and an electric pump for the Coolant Heat Storage tank).

    The CHS tank is a thermos that can keep a few quarts of coolant toasty for a few days. On a cold start the ECM turns a pump on to move that hot coolant into the ICE and help the engine to warm up quicker (to reduce emissions). There's a sensor at the tank to monitor temperature. If the ECM commands the pump on and expects the temperature to change but it doesn't, then it concludes that the CHS pump don't work. Could be the pump, wiring, or the control relay (not an uncommon fault).

    Posted via the PriusChat mobile app.
     
    #4 mr_guy_mann, Oct 26, 2021
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