Going overboard?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by benwray1, Jun 28, 2025.

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  1. Mendel Leisk

    Mendel Leisk MMX GEN III

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    #21 Mendel Leisk, Jul 1, 2025 at 11:10 AM
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  2. adrtho4

    adrtho4 Junior Member

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    Nuts about Bolts videos and Gasket Masters for your generation prius. That's what I followed. Make sure you torque things properly, consult the repair manual for the specs. Take the time to quadruple check that all the connections are secured and there is nothing unplugged.
     
    #22 adrtho4, Jul 1, 2025 at 11:26 AM
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  3. benwray1

    benwray1 Junior Member

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    Update 7/1/25

    I realized I had lost a hose, and found it, dropped in front of the radiator, thankfully! I looked at several videos to compare the purge valve placement, etc. The only thing that I can't figure out is this 8-inch electrical connector, on the passenger side, down by the water pump. It's plugged in on one end, but not the other. I'm not sure where it goes. Any tips? It's like an adapter from one harness to another.

    Also, my check hybrid system is on, but I think it's because I ran the 12V battery down. I have it on a battery charger right now. Any tips on this are appreciated as well. I am truly thankful for all of the advice.
     
    #23 benwray1, Jul 2, 2025 at 12:27 AM
  4. benwray1

    benwray1 Junior Member

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    Update: I figured out where everything went. Now, I have a Check Hybrid System message after I got it all back together. So I'm charging the 12V battery overnight.
     
    #24 benwray1, Jul 2, 2025 at 3:06 AM
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  5. Brian1954

    Brian1954 Senior Member

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    What trouble codes do you have?
     
    #25 Brian1954, Jul 2, 2025 at 9:21 AM
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  6. adrtho4

    adrtho4 Junior Member

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    Did you disconnect the inverter cables? I did and I got the same "Check Hybrid System" message. What I did to resolve it was ensure all cables were seated and tightened properly. Even that one cable to the side. What also helped was a blue tooth obd2 scanner and the Dr Prius app, but Autel AP2000 has been recommended here.

    You can use something like that to get an estimate of your hybrid battery life as well as your 12v battery.
     
    #26 adrtho4, Jul 2, 2025 at 9:24 AM
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  7. NutzAboutBolts

    NutzAboutBolts Senior Member

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    what did you do to the vehicle?
     
    #27 NutzAboutBolts, Jul 2, 2025 at 4:16 PM
  8. ASRDogman

    ASRDogman Senior Member

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    You're going to have to clear that code, it won't go away on its own.
    I "think" if you disconnect the 12v battery, (while you charge it) for an hour or so it will clear
    all the codes.

     
    #28 ASRDogman, Jul 2, 2025 at 5:20 PM
  9. NutzAboutBolts

    NutzAboutBolts Senior Member

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    funny thing is, I finished the headgasket replacement, plugged back in the service port and 12v cable. No check engine light, I didn’t have to clear the code :D
     
    #29 NutzAboutBolts, Jul 2, 2025 at 6:05 PM
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  10. ASRDogman

    ASRDogman Senior Member

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    Nothing funny about that. You just got everything connected correctly, and the first time! :)

     
    #30 ASRDogman, Jul 2, 2025 at 6:23 PM
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  11. NutzAboutBolts

    NutzAboutBolts Senior Member

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    I kept all the nuts and bolts organized, so it was just remove and install it in place (y)
     
    #31 NutzAboutBolts, Jul 2, 2025 at 8:25 PM
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  12. benwray1

    benwray1 Junior Member

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    I didn't have any trouble codes, just "Check Hybrid System." I figured out that I didn't reinstall the orange HV battery plug correctly haha! I did charge the 12V battery overnight just to make sure, but now everything is good. I've driven it for a couple days now, and I think I'm in good shape. I got a scary rattle when I turned the engine on for the first time after all this work, but it seemed to just be that one time. Also, I'm not sure I replaced one of the EGR gaskets, the one with the prongs that come out to grip the surface, but it's difficult to find a replacement. I may see if the Toyota dealer has one.

    Also, I got super good gas mileage for the first few minutes, but then it seems to be back to around where it was, about 40 mpg. Not complaining, but I was hoping that it would improve, especially after cleaning the fuel injectors.

    I'm going on a road trip this weekend, about 7.5 hours each way, so I'm glad I got to drive it for a couple of hours yesterday.

    I'm going to air up my tires a little over the recommended amount and see if that helps with the noise somewhat, although I will keep it in the safe range. I still feel like this car has louder tires than our other 2010 base prius, even though I just replaced them. Yes, we have two 2010 Priuses haha! But my son and I are both musicians, and these are great cars for lugging gear around from our house to where most of the gigs are in the KC area.
     
    #32 benwray1, Jul 4, 2025 at 8:21 PM
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  13. benwray1

    benwray1 Junior Member

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    see above
     
    #33 benwray1, Jul 4, 2025 at 8:23 PM
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  14. ASRDogman

    ASRDogman Senior Member

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    Toyota has all the gaskets....
    It's very likely the safety plug wasn't set correctly, it's kinda easy to do.

    The tires are the noise makers. Different tires are noisier than others...

     
    #34 ASRDogman, Jul 4, 2025 at 8:48 PM
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  15. Brian1954

    Brian1954 Senior Member

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    FYI. If you have the "Check Hybrid System" message, you have trouble code(s) that need to be read with a capable scanner.

    It would be a good idea to buy a Prius capable scanner for the next time you have problems with your cars. Read post #1 and then scroll down to post #37 in this thread, https://priuschat.com/index.php?posts/3246758
    You should choose a scanner that can communicate with all the ECUs (systems) in the car. A good choice is the Autel AP200.
     
    #35 Brian1954, Jul 4, 2025 at 10:30 PM
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