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So many codes... Initially P1116 and P1121, now also P0441, P0455, and P0456

Discussion in 'Gen 2 Prius Main Forum' started by DrTooth, Dec 7, 2022.

  1. DrTooth

    DrTooth Junior Member

    Joined:
    Jun 12, 2019
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    Location:
    California
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    2007 Prius, 190k miles
    It started a few weeks ago with P0441 and P1116. I read up on it here, checked the coolant levels at both the reservoir and the radiator, which were good, and figured it's likely the coolant control valve that needs to be replaced.
    I've been strapped for time so I had my mechanic check it to see if their quote would be worth it for me. They recommended changing the coolant temp sensor first, $90, which was much cheaper than the around $850 for replacing the coolant control valve so we went with that. They cleared the codes and after driving a few days the P0441 and P1116 came back.
    So I've been meaning to tackle the coolant control valve and haven't made the time. I also read here that it's ok to drive so I have been.
    I reran my codes today and I still have P0441 and P1116, but now I also have P0441, P0455, and P0456. The three new ones I'm about to research here on PriusChat but I figured I'd get this post up first.

    A few possibly related notes:
    - My heat has been working this whole time (I've read that it usually doesn't work when the coolant control valve is stuck)
    - Mechanic recommended spark plug change since what's been in there isn't OEM, so I did that myself a couple weeks ago (Denso SK16R11 Iridium)

    Thanks in advance for any and all help!
     
    #1 DrTooth, Dec 7, 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
    So, the P1116 indicates something is off with the temperature sensor for the Coolant Heat Storage tank. (sensor is at the bottom of the silver tank that's behind and below the Left headlight). Did the mechanic find any problem with the old sensor? Did he replace that sensor or the ENGINE Coolant Temperature sensor?

    I would be using a capable scantool to monitor ECT and CHS temperature readings during a "cold start" - ignition ON (but not ready), turn heater fan off, connect scantool and view the 2 temperature data. Then go READY and watch while the CHS pump runs but before the ICE (engine) starts.

    Here's a capture from my 2006 after a 10 hour soak at about 40°F. You can see the ECT ("coolant temp") and CHS ("tank outlet") go up about 100° before they drop some and the ICE starts.

    IMG_20221118_192203682.jpeg


    P0441, P0455, and P0456 are all codes for the EVAPorative emissions system (the EVAP deals with gasoline vapors from the fuel tank). You need to do some diagnostic testing as "shotgun" parts replacement can end up causing more problems instead of fixing things. (That said, a visual inspection of the gas cap, and underhood vacuum lines isn't a bad idea.)


    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, Dec 7, 2022
    Last edited: Dec 7, 2022
  3. DrTooth

    DrTooth Junior Member

    Joined:
    Jun 12, 2019
    10
    1
    0
    Location:
    California
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    Thank you, I'll figure out if my scantool app can check those and report back.
     
    #3 DrTooth, Dec 10, 2022
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