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2015 Prius ECM Recovery Possible?

Discussion in 'Gen 3 Prius Technical Discussion' started by xjrguy, Jul 23, 2017.

  1. xjrguy

    xjrguy New Member

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    2015 Prius
    Model:
    Five
    All, I bought a Mongoose Pro cable and a TechStream subscription to check for any TSBs and calibration updates for my 2015 Prius Five.

    There was only one update and I proceeded to start the update to reflash and update my car's ECM.

    Well, something went wrong and it didn't finish. I believe I didn't key off and back on during the step where CAL 1 was being loaded.

    Now my car has almost all the warning lights lit up and it won't work.

    It does turn on and go with battery only, but I ended up just putting it in my garage to save any juice in case it needs to be towed to the dealer.

    Since I have a full blown TechStream subscription (at least for another day) and a sanctioned Toyota J2534 programming cable, is there any way for me to force flash a calibration on to my ECM?

    Any help would be greatly appreciated and hello to every one. I have been lurking here since I bought my car.

    Thanks in advance!
     
    #1 xjrguy, Jul 23, 2017
  2. xjrguy

    xjrguy New Member

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    To add to this, when I try to reflash the ECM now Calibration Update Wizard (Toyota's Flash software) complains that it can't retrieve a calibration from the current ECM. I am assuming that is due to it being erased at the first update attempt.

    I know Chrysler's tool allows a force re-load of the PCM software. Does Toyota allow this and if so, how is it done.

    TechStream still talks to the car and can see all the modules. It shows an * next to ECM AND ECT.
     
    #2 xjrguy, Jul 23, 2017
  3. Elektroingenieur

    Elektroingenieur Senior Member

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    I don’t know of a procedure to recover from a failed programming attempt, but perhaps someone more experienced will have something to share. If there is a recovery procedure that can be used in the field, I would have expected Toyota to describe it, either in T-SB-0134-16, “Techstream ECU Flash Reprogramming Procedure,” or in the service bulletin describing the calibration update you tried to install.

    If you use Techstream to run a Health Check now, what DTCs are reported, and from which ECUs? Can you access any of the Data List/Active Test features for the ECM, or is it completely non-responsive?

    If no one has any better ideas, before you replace the ECM with a new one, I suppose you could try disconnecting the negative terminal from the auxiliary (12-volt) battery, waiting a few minutes, and reconnecting it, to reset the ECM and other ECUs. The torque specification for the battery terminal, and any other required reinitialization, should be stated in the Repair Manual. I emphasize that this is just my own speculation, not a Toyota procedure or something I’ve done before, and it might make things worse, not better—proceed at your own risk. (But please do tell us if it works.)
     
    #3 Elektroingenieur, Jul 23, 2017
  4. xjrguy

    xjrguy New Member

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    thanks so much for the reply. I disconnected the negative for a few minutes and that reset the car and the NAV system did its checks and rebooted. The problem still remains. I connected TechStream and ran the health check and there are DTCs stored for U0100 which is no communication to ECM. ("Lost Communication with ECM/PCM "A") is the error.

    I ran a CAN bus check and it too shows the ECM in red as non responsive.

    For the heck of it I selected the ECM when running a calibration check and it basically just skips over it and ignores it.

    I have the CUW file that would fix this problem if I could force flash the ECU but it seems I can't get it into any mode to receive the CUW file I downloaded yesterday. I'm hoping it's not bricked and there is some flash recovery mode I can use if someone knows it. Considering I have most of the tools (Techstream, active TIS account and J2534 cable) I am hoping there is a method I can use to force that CUW file to flash to the ECM.
     
    #4 xjrguy, Jul 23, 2017
  5. Elektroingenieur

    Elektroingenieur Senior Member

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    Have a look at this fascinating paper, “Adventures in Automotive Networks and Control Units” (PDF), and its accompanying code. Perhaps the authors’ toyota_flasher.py sample could be adapted to work with your ECM, to put it into programming mode, without checking the existing calibration version, and then write the calibration data from your .CUW file.

    Obviously, you’d be taking some risks with this: sending arbitrary commands over the CAN bus might damage other ECUs, and even if everything seemed to work, you might be left with an ECM with corrupted firmware that could malfunction, causing a sudden loss of power, unintended acceleration, or serious damage to the engine, for example. Unless you can use a recovery technique approved by Toyota, clearly the safest course is to replace the ECM with another one.

    You might also try contacting TechInfo Support (877-762-7666) tomorrow; I have no idea if they would have any helpful advice to give you, or if they would just refer you to a Toyota dealer.
     
    #5 Elektroingenieur, Jul 23, 2017
  6. xjrguy

    xjrguy New Member

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    Thanks again. We are on the same wavelength!! I read that entire site and article and had the same thoughts. Problem is they used a different vendor's cable and the DLL's don't match the DrewTech cable I have. I'm going to call the dealer tomorrow to see if there is anyway I can put this into a recovery mode before throwing in the towel. Unless there are any other ideas. I greatly appreciate the replies!
     
    #6 xjrguy, Jul 23, 2017
  7. xjrguy

    xjrguy New Member

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    Brought it into dealer. They diagnosed problem as main wiring harness needing replacement.

    ECM was apparently not replaced and car is working now after main harness replacement, unless a new ECM is part of that.
     
    #7 xjrguy, Aug 16, 2017
  8. StarCaller

    StarCaller Senior Member

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    that set you back how much?
     
    #8 StarCaller, Aug 17, 2017
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