1. Attachments are working again! Check out this thread for more details and to report any other bugs.

P2601 Possible bad CHS Pump?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by WestonP, Nov 15, 2018.

  1. WestonP

    WestonP Junior Member

    Joined:
    May 26, 2017
    15
    3
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    Two
    I have recently gotten a check engine light indicating a P2601 code. I was almost positive it was the inverter coolant pump, so I replaced it just yesterday. I cleared the engine code yesterday only to find this morning that it has returned.

    Either way, it's good i replaced that pump because it was bound to fail at some point, but I now realize that the pump I need to replace is the Coolant Heat Storage Tank Pump, or the relay is bad. The pump was pretty loud and roudy before it ended up quitting on me, so I can very well assume its the pump not the relay. My question would be, is this pump relatively easy to replace? I haven't seen any how to's on this, or even pictures of where it is.
     
    #1 WestonP, Nov 15, 2018
  2. audiodave

    audiodave Active Member

    Joined:
    Feb 3, 2017
    783
    268
    0
    Location:
    US
    Vehicle:
    2004 Prius
    Model:
    Five
    I thought it's just a valve for that tank. Engine water pump circulates that.

    Posted via the PriusChat mobile app.
     
    #2 audiodave, Nov 15, 2018
  3. WestonP

    WestonP Junior Member

    Joined:
    May 26, 2017
    15
    3
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    Two
    Correct, the engine water pump does circulate the coolant but I'm referring to the coolant heat storage tank which stores hot coolant. With the pump no longer running it will no longer transfer hot coolant to the tank which isn't crucial to the cooling of the engine but it throws an error code nonetheless.
     
    #3 WestonP, Nov 15, 2018
  4. audiodave

    audiodave Active Member

    Joined:
    Feb 3, 2017
    783
    268
    0
    Location:
    US
    Vehicle:
    2004 Prius
    Model:
    Five
    I wasn't aware of a separate pump for that. Thought just a valve and used engine pump for that.

    Posted via the PriusChat mobile app.
     
    #4 audiodave, Nov 15, 2018
  5. audiodave

    audiodave Active Member

    Joined:
    Feb 3, 2017
    783
    268
    0
    Location:
    US
    Vehicle:
    2004 Prius
    Model:
    Five
    The coolant system even more complicated than I thought. Lol

    Posted via the PriusChat mobile app.
     
    #5 audiodave, Nov 15, 2018
  6. WestonP

    WestonP Junior Member

    Joined:
    May 26, 2017
    15
    3
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    Two
    Update*

    I checked the relay and its good. I also checked the wiring and found no cut wires or issues there. Once I get paid I'll be ordering the pump.
     
    #6 WestonP, Nov 15, 2018
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    You just have to jack up the driver's front wheel, remove the tire, and remove the front of the fender liner. Then you will have access to the CHS canister and the pump is mounted adjacent to the canister.

    If you had been used to hearing the pump run upon startup and shutdown, and no longer hear it, then it is a good call that the pump, relay or associated wiring is bad.

    You should be able to measure 12V from one of the switched terminals of the relay to body ground, at all times. You can also short the switched terminals at the relay socket to prove that the pump is bad (assuming that the wiring is good.) And of course, the ultimate proof the pump is bad is to use a 12V source and apply voltage directly to the pump terminals.

    See my posts #22 and #42 in this string, along with the surrounding discussion, to learn how to run the CHS pump manually which is necessary when refilling the engine coolant system. Alternatively, this can be performed under software control using Toyota Techstream (or Mini VCI).
    Changing engine coolant | Page 2 | PriusChat
     
    #7 Patrick Wong, Nov 15, 2018
(You must log in or sign up to post here.)