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Water temp sensor issue,

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by FnRedPrius, May 20, 2019.

  1. FnRedPrius

    FnRedPrius Active Member

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    I know the gen 4 installation doesn't really affect this except for sensor plug being interfered with by the EGR. I thought I might have had enough clearance , especially since I had heated and moved that small hose connector that was right below it. Anyway, the EGR interfered to the point that it completely cut one of the wires going to the water temp sensor and the CEL came on. I went and had codes read just to make sure and it was, and it was. I removed the EGR and replaced the connector, then I introduced the EGR to the bench grinder and removed about 30% of that lower tab. I did this on Friday and the CEL still hasn't cleared. I ran it back to Auto Zombies and still only showing the temp sensor. Just to make sure, is there anywhere else I should be looking? I may try to borrow a reader and clear it in the morning.

    Would anybody happen to have the part number for that connector? I kinda looked for it last night while multi-tasking between The Life and Times of Judge Roy Bean and attempting to create a shortage of Sunset Blush in the fridge. Worst case will be getting one out of a salvage. I just want to have one on hand.
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    It's probably fresh in your mind LOL, but did you just do a 4th gen engine into 3rd swap?

    (Ah, checking your history, you did.)
     
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  3. FnRedPrius

    FnRedPrius Active Member

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    Okie Doke, dumbass attack. Rather than looking at parts fiches, I did a GOGGLE search and found bunches of aftermarket ones and maybe the OEM part number.. Now we search s'more.

    AND after a 3 more minutes of searching, I may have an alternate solution..
    Not being happy with the upper radiator hose mod, I bought a water pipe, Water Pipe - Toyota (16577-37080) | Toyota Parts

    Now this part has a threaded port, and after re-thinking this I am going to see if the temp sensor will fit that port., I'll let y'all know
     
    #3 FnRedPrius, May 20, 2019
    Last edited: May 20, 2019
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    @Ragingfit videos do a couple of mods in that area. One being largish diameter pipe extension, and the other involving soldering some extension wire on a sensor, IIRC? He also grinds a nub off the corner of the 4th gen cylinder head, where the EGR's fouling it slightly. This is all old news?
     
  5. FnRedPrius

    FnRedPrius Active Member

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    Yep. I watched his vids and I bought the 1 inch pipe, but when I was doing it I bought the long 2016 hose and then used a plastic union (hose repair) but everything was in standard sizes so no leak but not happy with it easier. Since I was in the dealership anyway I ordered the connector pipe to use to replace the repair union but just haven't tried to find out what sensor goes into that hole. After thinking about it (since it is in the front of my mind instead of the back) I bet it will be the temp sensor and I just happen to have an extra one. I also took the time to heat and bend one of the hose connections on the EGR that actually made it easier for one of the other hoses to connect. Part of my problem with this repair was that when I cut the wire at the connector, it was almost too short to add the new wire to. I cut the original connector off near the connector and then cut the one from the donor engine where it entered the harness trunk, so I only had to make two connections rather than 4. This was probably just poor routing on my part, but I may end up with a much better solution. Depending on how I feel when I get off in the morning, I may actually have an answer before I go to bed as to the connector pipe being a solution.

    And just stick this in the back of your mind. I finally cleaned up my mess from the engine swap and I cut every connector off of the donor engine harness, so I new have a full set of the connectors if anybody needs anything. I also have a Gen 4 flywheel and damper, and complete EGR.
     
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  6. FnRedPrius

    FnRedPrius Active Member

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    New turn of the worm... The port fitting is actually a smooth bore with a place for a C-clip to retain the sensor. I still can't find what part goes in it. I guess a call to a big name Toyota parts department is in order for tomorrow.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    I've got a vague recollection, in one of @Ragingfit 's videos he mentions putting a sensor in a pipe, just to seal it. It's used on 4th gen but not on third. Is that in any way relevant?
     
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  8. FnRedPrius

    FnRedPrius Active Member

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    Yep, I'll go back and look thru his stuff. I know the pipe is from Gen 4, but I can't find anything for the sensor on any of the Gen 4 fiches.
    Maybe I can try to be productive during my last 25 minutes of work and spread out my search terms and formats....
     
  9. Ragingfit

    Ragingfit Active Member

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  10. Ragingfit

    Ragingfit Active Member

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    I know one of the first guys to do the swap, I think
    @Joele3
    actually tapped the hole in that "pipe" to accept a plug or a temp sensor.
     
  11. FnRedPrius

    FnRedPrius Active Member

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    I went back thru the @Ragingfit 's video and did a sccreen shot @1:42 and took it to the closest Toyota parts department. I told her what I was looking for and she asked for the VIN and had to get help when I told her that the car had been there, but not the engine. She grabbed a tech who didn't believe that I had done the IV to III swap until I showed him a pic. They then found the sensor. Toyo OEM # 89422-47010 and the retaining clip is 90468-14043. She quoted me $103 for the sensor and $3 for the clip. :eek:
    When I got home, I went online and found the sensor for $53-58 and called an on-line parts dept and the dude said that the sensor would be a 2 day shipping and the clip did not show to be available in the US. We talked for a minute and he said that he thought that he had seen an increase in Gen III stuff and then he looked up Priuschat and he was going to have a lot of reading to do. I should be able to find the clip at NAPA or Carquest.

    We'll let you know.
     
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  12. johnnychimpo

    johnnychimpo Active Member

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    How did the end? Question there are two temp sensors is the one on top of egr only for overheat light? Or does it provide temp reading? I had the same issue with egr and wire. I repaired wire and installed new sensor. To test I disconnected the sensor above egr cooler and now I don't get temp reading. I plug it back in and overheat light goes away and I get temp readings. Can anyone clarify the function of each sensor?
     
  13. ChapmanF

    ChapmanF Senior Member

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    The one with the brown and pink wires supplies a temperature reading to the ECM.

    The one with the black and white wires supplies a temperature signal to the overheat indicator on the dash.

    I am suffering from déjà vu.
     
  14. johnnychimpo

    johnnychimpo Active Member

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    Sorry I get that. Ok so when you say ECU is this info strictly for ECU and not shown in the ODB? Yes I know the one with the pink wire underneath the EGR. I only say because when I disconnect the one on the stop my odbe stope displaying the temp. leading me to beleive the one on top of the egr does two things provide additional temp reading and overheat indicator int the dash.
     
  15. ChapmanF

    ChapmanF Senior Member

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    It would help if you could indicate what you are using for your readings from the OBD (On Board Diagnostics) and if it indicates which ECU and PID it is reading the value from.

    It will probably work out best to keep one thread active on the question so the information can be developed there without being repeatedly lost. It looks like your thread over here might be shaping up best for that.