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CHS related CEL question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by reighnman, Jun 26, 2011.

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  1. reighnman

    reighnman New Member

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    I figure I might as well replace the temp sensor while I'm at it, so going to order one today with the CCV. Looking at this post it seems the P/N for the CHS temp sensor is 89429-47010, is that correct? TW shows it as:

    8942947010 $66.12 $0.00 $49.59 SENSOR, TEMPERATURE

    Not very specific but I can't find any temp sensor specifically related to the CHS.
     
    #21 reighnman, Sep 19, 2011
  2. reighnman

    reighnman New Member

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    Well I pulled the harness of the CHS temp sensor to test the ohms between the pins and as I did the boot on the plug crumbled exposing the 2 wires of the plug and bunch of corrosion inside the plug. I also noticed the shielding of the brown/ground wire is broken exposing the wire so it looks like I need to cut off the plug and replace it. Any idea of where I can pickup one of these 2 pin plugs to splice/solder back on?
     
    #22 reighnman, Sep 19, 2011
  3. 2009Prius

    2009Prius A Wimpy DIYer

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    Try your local junk yard or autobeyours.com
    Good luck! :)
     
    #23 2009Prius, Sep 20, 2011
  4. reighnman

    reighnman New Member

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    Thanks, tried autobeyours and apparently these plugs (the pigtails at least) are hard to come by.
     
    #24 reighnman, Sep 20, 2011
  5. seilerts

    seilerts Battery Curmudgeon

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    Are you saying the sensor itself has only 3 ohms? It should be 100-1000 -- i.e. thermistor resistance. Or the connector side is 3 Ohms (should be 10K or more)? Anyway, glad to hear that you've got this one figured out.

    I think you have the right part number if you are replacing the sensor. For some reason, the shop manual calls it an "oil temperature sensor", which is how it is described on toyodiy.

    It just so happens that I have a semi-complete engine and main wiring harnesses out of a Sequoia, and open access to the CHS on a Prius. I'll take a look when I get down to the man cave later to see if I can find a connector that will work for you.
     
    #25 seilerts, Sep 20, 2011
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  6. reighnman

    reighnman New Member

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    I tested the ohms between the 2 wires on the connector (the brown ground wire and the other I think was white), hoping to confirm an issue with the ground but I don't know if that's normal or not.

    Champion confirmed the p/n on the temp sensor so I ordered it yesterday with the ccv, hopefully it gets here before the weekend.

    I'd say it's still far from figured out but the help has been great.

    To clear the P codes it's connecting a wire between the 2 pins on the ODB connector, turning the car on and pressing the break pedal 8x within 5 sec correct? I've also been unplugging the battery for 10min when I do so. Just want to make sure I'm clearing the codes correctly before I take it in to check if the o2 sensor code is gone with the temp sensor plug being disconnected.
     
    #26 reighnman, Sep 20, 2011
  7. seilerts

    seilerts Battery Curmudgeon

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    Well, that figures. The connector is fairly unique. I couldn't find a match off either Sequoia. A dealer should sell the pigtail.

    The battery negative disconnect is sufficient to reset P codes. Jumpering the OBD will clear permanent brake C codes.
     
    #27 seilerts, Sep 20, 2011
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  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. It is necessary to connect a jumper on the OBD-II connector only if your car has logged skid control DTC.

    2. If the car only has hybrid vehicle or engine ECU DTC, all you have to do is to disconnect the 12V battery for a few minutes to clear the memory in those ECUs.

    3. As seilerts mentioned, the ohmmeter test should show a much higher resistance whether you are measuring the sensor or the wiring harness. I suggest you cut off the bad wiring harness connector and measure the resistance across the two wires. If you still get 3 ohms then you have a problem with a damaged wiring harness and that needs to be figured out.

    4. If your resistance test in #3 shows an acceptable result regarding the existing sensor and the wires; and you have the ability to solder, I suggest you directly solder the bare wires to the existing sensor after cleaning the sensor pins so that they can be soldered. Then see what happens. You can always install the new sensor and a replacement wiring harness connector later.
     
    #28 Patrick Wong, Sep 20, 2011
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  9. reighnman

    reighnman New Member

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    I cut off the harness and it still measures 3 ohms, so looks like I'll have to back track a ways and see where it goes.
     
    #29 reighnman, Sep 20, 2011
  10. reighnman

    reighnman New Member

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    So yesterday while she was at work her boss had the shop mechanic take a look, he found the sensor plug I cut off (I was in the process of finding a replacement) and put one on he found from a dodge.

    It did clear all the codes (P1037/P1116/P1118) so the issue seemed to be resolved, but she then called me on the way home from work saying that she had to pull over and turn the car off due to overheating. When I got there I saw the CHS drain cock was wet so figured he drained the tank or pulled the sensor while troubleshooting it. Spent an hour or so bleeding air out of the system and so far so good, no more codes and no overheating. I did notice the heater isn't running very hot so there is probably more air I need to get out, but I'll get to that tonight.

    Thanks for all the help troubleshooting it down to the wiring issue, I returned all the cooling related parts I was about to replace so saved a few hundred bucks (unfortunately I already replaced the o2 sensor). Will update again if everything stays good :)
     
    #30 reighnman, Sep 21, 2011
  11. seilerts

    seilerts Battery Curmudgeon

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    Found the plug off a Dodge! :eek:

    Glad to hear that it all worked out. Now you are an expert!
     
    #31 seilerts, Sep 21, 2011
  12. veegish

    veegish Junior Member

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    I've been fighting code P0137 on my 2007 (220K miles) for three months! I've avoided a ticket so far, but I'm certain it's only a matter of time.

    I've replaced the A/F sensor, the CAT, the O2 sensor (twice), spark plugs, the doughnut gasket, and I've cleaned the throttle body and the MAF sensor. This post is the first time I've seen any indication that maybe it's a bad wire or connection that is causing me trouble. Is this open/grounding issue common? I'll check it when I get home tonight and see if I can track it down.
     
    #32 veegish, Jul 31, 2017
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