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P3120 and P3125 with subcodes

Discussion in 'Generation 1 Prius Discussion' started by Haba Catalin, Mar 7, 2012.

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  1. Haba Catalin

    Haba Catalin New Member

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    First I want to thank all those who are members on this forum because I read and learned a lot.

    I bought my Prius after I tested the car around town and on the highway and went smoothly.
    I drove the car about 200 km after the warning came on board, high temperature and cold engine warning (red and blue).
    Stopped the car and I found nothing to be hot (engine or inverter)
    I rebooted and the errors disappeared but reappeared and on the highway (120 km) car no longer accelerate, pedal did not respond.
    Stopped and restarted repeatedly trying to get as close to home and a Toyota service.
    High and low temperature have appeared and disappeared after stopped and restarted.
    Warnings appear together, none or only one of them.

    But after 600 km appeared turtle on board and the car stopped. I was unable to start.
    They came from Toyota and were able to start with another auxiliary battery and ran 10 km with a tester on the dashboard (at full throttle and the car accelerated 1 km / sec until it reached 60 km / h then accelerated normal to 125km/h. When he put the foot on brake and after that tried to accelerate again the pedal was non responsive and the car stopped again and they towed it.

    Next day they told me that the ECU is faulty (the one located behind the glove compartment) together with the Auxiliary Battery.(1100 Euro ECU).They told me that the temperature sensor is 200 degrees Celsius with a cold engine.

    We towed the car to another service closer to home (1300 km) and asked a second opinion telling me that is defective inverter
    I decided to buy an ECU. (220 Euro/ second hand)

    Meanwhile my traction battery died after they tried to start the car many times.

    After I charged the traction battery (one module at a time), whole battery shown after charging 301 V.
    Now I have the following :

    P3120 HV transaxle / Wire harness
    INF. Code 249 (Open or +B short in motor temperature sensor)

    P3125 Converter & Inverter assembly / Wire harness
    INF. Code 287 (Inverter internal short)
    INF. Code 295 (when there is a history that the state of malfunction continued during inverter fail safe mode)

    Car starts but does not go forward or backward. When I put it in D or R it seems like the MG2 doesn’t work. That’s were the sensor is.
    They removed the oil from MG2 and put a resistor instead of the sensor to show 27 degrees Celsius and someone started it without oil, and in 5-10 seconds something exploded and smoke came out I suspect from inside MG2.

    I apologize if I misspelled something.

    Thanks for any advice
     
    #1 Haba Catalin, Mar 7, 2012
  2. electrontechnik

    electrontechnik Member

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    #2 electrontechnik, Mar 7, 2012
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  3. Haba Catalin

    Haba Catalin New Member

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    When the car stopped both batteries were discharged (auxiliary and traction).The auxiliary battery it's a solar 24Ah and was installed 03/11/2008.
    I tried to jump start the car but I think the traction battery at that moment doesn't have enough juice to start the car.
    After I let it sit for ~6 hours I came back with someone from toyota, with another auxiliary battery, and he could start it and drove for 10 km until the car stopped.
    He drove it with a tester on the dashboard (at full throttle the car hardly accelerated 1 km / sec until it reached ~60 km / h then accelerated normal to 125 km/h. When he put the foot on brake, and after that tried to accelerate again, the acceleration pedal was non responsive and the car stopped again and they towed it to service.

    When he start the car I tested the auxiliary battery, put by the technician, and I saw on the multimeter 14V.This means the inverter it's OK ?
    If MG2 is bad why I have also P3125 they are related :confused:? A short in MG2(because I also have the sensor with 200 degrees Celsius inside it) I think is the cause.

    Other suggestions are appreciated.
     
    #3 Haba Catalin, Mar 9, 2012
  4. Catalinux

    Catalinux Junior Member

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    See that is another post related about this, do you have Cruise? if yes, then try to drive the car with cruise, if you don't have cruise verify the accelerator pedal (it is like a potentiometer), Search for accelerator pedal threads here. Hope it helps
     
    #4 Catalinux, Mar 9, 2012
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  5. Haba Catalin

    Haba Catalin New Member

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    Thanks.I already read it.
    No, I don't have cruise.
    I don't thing is a problem with accelerator pedal because,if I remember well, the car behaves like that when the sensor from MG2(hot) appear on dashboard.

    Make any sense :confused: or it's only a coincidence ?
     
    #5 Haba Catalin, Mar 9, 2012
  6. Catalinux

    Catalinux Junior Member

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    That's your problem, solve it first
     
    #6 Catalinux, Mar 9, 2012
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  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    It is pretty obvious that the transaxle is bad. It is possible that the inverter may be bad. If you measure 14V at the 12V battery that shows the DC/DC converter in the inverter is working, but other parts of the inverter circuitry may not be working.

    Hence, replace the transaxle first, but don't be surprised if you will also have to replace the inverter. Considering your car is 11 years old, you'll have to decide whether it should be repaired or sent to the salvage yard. Good luck.
     
    #7 Patrick Wong, Mar 9, 2012
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  8. electrontechnik

    electrontechnik Member

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    #8 electrontechnik, Mar 10, 2012
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  9. Haba Catalin

    Haba Catalin New Member

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    Where I could find exactly what MG1,MG2 and Inverter do.I saw the clips but I want to know exactly the role of each one.I have a short in both Converter & Inverter assembly and HV transaxle or it's in only one place (I supose in MG2) and because of this shows also in the inverter ?



    "MG2, the larger of the two generators inside the transmission assembly, is notorious for premature failure.The windings of MG2 shorting out and failing."
    Where in the MG2 is the temperature sensor ?
    If it's in the stator and the windings were melted (shorted)this explains the 200 degrees Celsius displayed.
    If this is the only fault of the MG2 why they don't sell only the windings ? Did someone tried to rebuild the windings ?
     
    #9 Haba Catalin, Mar 12, 2012
  10. seilerts

    seilerts Battery Curmudgeon

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    #10 seilerts, Mar 12, 2012
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  11. Haba Catalin

    Haba Catalin New Member

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    I already read it, thanks to "electrontechnik".
    I don't have a P3009, at least not yet, but my car behaves similar.:deadhorse:
    DTC P3009 - high voltage ground fault.
     
    #11 Haba Catalin, Mar 13, 2012
  12. ChapmanF

    ChapmanF Senior Member

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    You might also want to look into this approach, replacing only the windings.

    It still requires buying an entire MG2 because the windings are not sold separately, but it requires much less labor and shop time than actually replacing MG2 whole.

    It seems that there are tricky parts to the procedure that were figured out by Jack Rosebro of Perfect Sky Hybrid Training, and their business model is to sell training on how to do it. I don't know whether they could get training materials to you in Ro, but maybe they would.

    -Chap
     
    #12 ChapmanF, Mar 13, 2012
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  13. seilerts

    seilerts Battery Curmudgeon

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    Oops, I didn't see that it had been linked to already. Sorry about that.

    MG2 is the main drive electric motor. The other electric motor, MG1, is the "generator", it allows the gas engine to charge the electric batter, as well as making it possible for the transmission to have a CVT quality. MG2 is the part of the transaxle most likely to go bad. In spite of the "you can't rebuild these" message from Art's, it should be possible to make one good one out of two bad ones, if you can find a core unit that has a good MG2 but e.g. a cracked case.

    Have you examined the transmission fluid? Have you tested the windings for resistance? Good fluid, low winding resistance, and high insulation resistance could point to it being simply the inverter that it bad. But it would be a surprise if it was simply the inverter.
     
    #13 seilerts, Mar 13, 2012
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  14. ChapmanF

    ChapmanF Senior Member

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    Good thought, that probably is cheaper than buying a new MG2. And if nothing is wrong but the windings, you could still use the Jack Rosebro technique and swap only the windings; then you avoid changing any rotating parts or bearings, so you don't have to select and order the right preload-adjusting shims by carrier pigeon from Japan, which was what led to the expensive month-long delay in the Art's story.

    Of course if you start with a used MG2 you'd want some way to know the winding insulation isn't about to fail.

    -Chap
     
    #14 ChapmanF, Mar 14, 2012
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  15. Haba Catalin

    Haba Catalin New Member

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    :thumb:Thanks. This is it.Exactly what I want to know.

    A short in the MG2(the cause) can show also a short in the Inverter.

    Common symptoms can include:

    1. Shudder during takeoff
    2. Louder whine during regenerative braking
    3. Temperature warning light (red thermometer)
    4. Master Warning Light (red triangle)
    5. Diagnostic Trouble Codes (DTCs):
    P3009: HV Leak to Ground -- I don't have [​IMG]​
    P3125, info code 287: Inverter Internal Short​
    P3120, info code 250: HV Transaxle Assembly Malfunction, Motor Temperature Sensor Performance Problem​

    ​

    ​

    ​
    A price for a new MG2 in Canada :confused:? Who can tell me ? I have a nice there and she can bring it to Romania.​

    ​

    ​
     
    #15 Haba Catalin, Mar 14, 2012
  16. Haba Catalin

    Haba Catalin New Member

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    Hello again,

    I took the car from Toyota and now the car sits in my backyard.I didn't have time and all the knoledge for this project and DIY doesn't look very good so far.

    I lift the left front side, remove the left wheel and I unscrewed all the screws accessing them from below the car (six of them were hard to reach and not very confortable to unscrew)

    Now I must find out how to let down the MG2 with or without removing the Inverter from above. I need only 15-20 cm to lower the MG2 so I can pull out the windings.

    If anybody know how to pull out MG2 step by step I will be grateful.
     
    #16 Haba Catalin, Jun 17, 2012
  17. joedirte

    joedirte Member

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    Go pay $15 and get all the documents online from Toyota TIS.

    Anyways, be very careful with the magnets and heavy windings. I'm betting Toyota has special tools, but the Lucious Garage youtube video shows her just dropping in it by hand.
     
    #17 joedirte, Jun 18, 2012
  18. Haba Catalin

    Haba Catalin New Member

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    Update.
    Burned MG2. Project DIY.
    Now I'm looking for a MG2.
     

    Attached Files:

    #18 Haba Catalin, Oct 4, 2012
  19. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Is there a motor rewind shop near you?
     
    #19 usnavystgc, Oct 4, 2012
  20. ChapmanF

    ChapmanF Senior Member

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    THANK YOU for the excellent series of photos. It is good to see the process in detail. I am curious about a couple of things:

    1. If it is not too inconvenient, could you weigh the rotor and stator and post the weights here? We know they are heavy, but to anybody contemplating a similar repair it might be helpful to know how heavy in advance.

    2. Of course you're getting into a procedure that can't even be found in the shop manuals or on TIS, because Toyota doesn't do it; the in-car MG2 stator replacement was figured out by Jack Rosebro, who trained Luscious Garage on it. In the Luscious blog about the procedure, one of the "significant discoveries" making it possible seems to concern the stator replacement by removing the endplate "with negligible disturbance to the motor resolver."

    The resolver is the pair of coils (built into the endplate, I think) that detect the exact rotational phase of the rotor, a signal needed by the HV ECU to correctly phase the inverter's drive to the motor. I have never seen one (not having taken my MG2 apart), but I believe it is the small donut of wire coils seen in your first photo, built into the endplate.

    Was there anything special you found you had to do while removing the endplate in order to avoid disturbing the resolver calibration? Could you describe the steps you used?

    In some of your later photos, what is the ring-like thing shown hanging from the rotor shaft? Is that something that was attached near the resolver?

    Looks like an interesting project!

    -Chap
     
    #20 ChapmanF, Oct 4, 2012
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