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Gas engine does not start

Discussion in 'Generation 1 Prius Discussion' started by fredtr, Oct 28, 2011.

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  1. fredtr

    fredtr Junior Member

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    I bought a 2001 Prius, partially disassembled. I have it to the point that I can drive it short distances, electric only and can really use help with the following:

    1. A picture or description of how/where the ECU mounts near the glove box. It is currently on the floor with the wires connected.

    2. A picture or diagram of the fuses/relays that are on the left side of the gas engine. There are a number of empty sockets, maybe I am just missing a relay. And I am missing the cover which says what is what.

    3. I have engine light and triangle warning, and made the mistake of taking manufacturers suggestion to upgrade firmware and software of my code reader which was talking to the Prius and no longer can, so I do not know what the error codes are. I should have the code reader back in a week or so.

    It also shows what I thing is a blue temperature indicator. Until I can read codes, is there someplace to check if MG1 is getting power to try to start the gas engine?

    I don't hear or feel anything to indicate MG1 is even trying to start the engine. Any suggestions etc., would be greatly appreciated.

    Thank-you,

    Fred
     
    #1 fredtr, Oct 28, 2011
  2. seilerts

    seilerts Battery Curmudgeon

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    Your best bet is to pony up $15 for a Standard weekend subscription to techinfo.toyota.com to download all service manuals.

    If the fuse for the ECM is blown/missing, then the engine will not start.

    Why did the prior owner tear things apart?
     
    #2 seilerts, Oct 28, 2011
  3. fredtr

    fredtr Junior Member

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    I don't know why it was torn apart. The owner had passed away. I transported what was assembled and then moved a larger amount of parts.

    Could you tell me where the ECM fuse is? Does ECM stand for Electronic Control Module? I would assume that at least most of them are working or I wouldn't be able to go to ready and run electric. Or maybe you are refering to just the control module for the engine?

    Thank-you.
     
    #3 fredtr, Oct 28, 2011
  4. seilerts

    seilerts Battery Curmudgeon

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    ECM = Engine. It has a special acronym since all other computers are called ECUs. The ECM is on the passenger side behind the glovebox/air conditioning vent. Fuse/relay labels and locations are all in the service manuals. EFI fuse and relay is in the big fuse box under the hood.
     
    #4 seilerts, Oct 28, 2011
  5. fredtr

    fredtr Junior Member

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    Thank-you. That must be the module that is now on the floor on the passenger side, but connected. It threw me because the label on it says HV ECU. It is also the one I'm trying to figure out how it attaches.

    I will check those relays and fuses, thanks again. I did mark the fan belt and the engine isn't being turned at all.
     
    #5 fredtr, Oct 28, 2011
  6. seilerts

    seilerts Battery Curmudgeon

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    The HV ECU lives right next to the ECM down in that corner. The wiring is typically very tight. It might be that the ECM is not even plugged in.
     
    #6 seilerts, Oct 28, 2011
  7. seilerts

    seilerts Battery Curmudgeon

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    Do you have a means for charging the HV battery? Typically, all 38 modules must be >7.2V. 7.5V is better.
     
    #7 seilerts, Oct 28, 2011
  8. ChapmanF

    ChapmanF Senior Member

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    If the HV ECU is down on the passenger floor, that sounds like about the right place. I believe it lives there, under the carpet.

    The ECM and the power-steering ECU are the two that snuggle up side-by-side to the right of the glove box, like two books on a shelf. At the moment I can't picture which is left/right of which, but the steering ECU has some smaller connectors with just 2 or 4 pins, and the ECM has a lotta pins. Do you have both of those boxes up there?

    -Chap
     
    #8 ChapmanF, Oct 28, 2011
  9. fredtr

    fredtr Junior Member

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    Yes, I replaced the bad cells and charged the HV battery, and can drive it electric only. It just won't even attempt to start the gas engine,
     
    #9 fredtr, Oct 28, 2011
  10. fredtr

    fredtr Junior Member

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    Thank-you, I will look for the ECM. The power steering does work, so it must be there.
     
    #10 fredtr, Oct 28, 2011
  11. fredtr

    fredtr Junior Member

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    Re: Gas engine does not start - P3125

    I borrowed a code reader, only code was P3125, with notation of SMR. The code reader did not have the ability to read the sub-code and SMR doesn't make a lot of sense since I can drive the car on the HV battery.

    Has anyone had experience with P3125 and the gas engine not turning/trying to start?
     
    #11 fredtr, Oct 28, 2011
  12. seilerts

    seilerts Battery Curmudgeon

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    P3125 is DC-DC converter. One point of troubleshooting is the wiring between the inverter and the HV ECU. Probably what the prior owner was trying to do.
     
    #12 seilerts, Oct 29, 2011
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  13. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    You should really find someone to scan your car with Toyota Techstream software so you can get all the hybrid specific codes and all the sub codes...otherwise you'll waste hours and $$$ trying to chase down the problem. It would almost be worthwhile to buy a Mongoose cable for $500, "acquire" the Techstream software via Internet, get the car running then sell the used Mongoose cable on Ebay for $100 less than you paid. It will be money well spent.

    Does your Prius have daytime running lights? that will affect the fuse/relay layouts.

    When you say it won't start, does it "crank/run" for 8 seconds then die? or do absolutely nothing?
     
    #13 3prongpaul, Oct 29, 2011
  14. fredtr

    fredtr Junior Member

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    It never tries to crank, the gas engine pulley does not budge. What I do know works is the part of the inverter that charges the low voltage battery, that voltage increases to 14 volts when car is ready. And since I can drive it around, the inverter can supply power to MG2. Since P3125 is in inverter code maybe it checks MG2 resistance of inductance and doesn't like what is sees?

    The code reader I sent back for repair is an autoingenuity, and will have to see if it will provide me the sub codes.

    More questions:

    1. It is the ECM ECU that is lying on the floor passenger side, and I might be probing this, but I still can't figure out where exactly it mounts. Can anyone help?

    2. Does anyone know what signal is sent to the inverter to send power to MG1 to start the has engine?

    Thank-you.
     
    #14 fredtr, Oct 29, 2011
  15. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    If you crawl under the car with car off you should be able to turn the crank pulley by hand since there is little compression until the ecu adjusts the intake valve timing. (You may have to remove the plastic dust shield on passenger side to reach the crank pulley).

    If crank pulley does not turn easily you may have a mechanical problem inside the engine.

    The Hybrid ECU mounts under the passenger floor carpet and is quite large. The engine ECU mounts behind the glovebox, and is smaller than the Hybrid ECU.
     
    #15 3prongpaul, Oct 29, 2011
  16. fredtr

    fredtr Junior Member

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    Thank-you, that was a good idea. The engine turns by hand easily.
     
    #16 fredtr, Oct 29, 2011
  17. paprius4030

    paprius4030 My first Prius

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    Was this car in a accident? If it was and I remember correctly, there is a switch that shuts off the fuel pump to prevent a fuel spill. If that switch isn't reset the fuel pump won't work and I wonder if it also prevents the ICE from trying to start?
     
    #17 paprius4030, Oct 29, 2011
  18. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    #18 3prongpaul, Oct 29, 2011
  19. fredtr

    fredtr Junior Member

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    Thank-you for posting the pictures.

    Regarding fuel pump switch. I don't believe that it has been in a recent accident.

    Is this correct that the gas engine should start when the key is turned to the start position?

    I did try pressing the brake and accelerator to the floor in drive to cause it to start and also tried turning on the air conditioning. Any one have any other suggestions?

    I also went into the diagnostic mode of the display and didn't learn anything. At one point I believe a green EXP or something similar apperared, I pressed it and it had a page letters and numbers, but I did not get a chance to write them down and have not been able to get the button to appear again.

    Playing with the car, the batteries are getting low so I'm currently charging them.
     
    #19 fredtr, Oct 29, 2011
  20. seilerts

    seilerts Battery Curmudgeon

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    Not if there is a failsafe condition, usually the case with P3125.

    As 3ProngPaul says, the 3 digit information code associated with P3125 will provide greater clarity. This will be a good test of your AutoEnginuity. Also, the inf code may be contained in the freeze frame data, if your other scanner can access that.

    AutoEnginuity is based in Mesa, so maybe you can trailer the car down to them if you still aren't satisfied. One of their claims is that they have trouble bug-fixing Gen 1 routines for lack of a vehicle to cross-check.
     
    #20 seilerts, Oct 29, 2011
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