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Accumuator Zero Down wont work in My Techstream--WHY?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Douglas88, Apr 30, 2022.

  1. Douglas88

    Douglas88 Junior Member

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    I am trying to bleed my brakes on 2nd gen Prius using Tech-stream, (the cheap one from ebay). I followed the manual step by step, doing as instructed till I got to "refresh high pressure line" which requires, among other things, to run accumulator zero down, 5 times, using tech-stream. When I use the active test section, to attempt this, I get a pop up that says "ECU can not perform the requested active test...please verify all vehicle conditions are met and try again" I have cleared DTC's, have powered down 12 volt system over night, etc. All conditions are as I understand them to be, but still can not proceed on the full bleed journey as this will not happen for me. Can anyone provide any insights?? Car is parked, motor relays are installed normally, all previous steps in the manual I have for a 2004 2nd gen Prius have been completed prior to arriving at this point, ignition is on, but not advanced into ready mode, IE no foot on brake when turning ignition on. ALL previous steps have worked, such as steps to bleed rear brakes, etc....etc. Thoughts on how to proceed????
     

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  2. ChapmanF

    ChapmanF Senior Member

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    In my Gen 3, I was nearly defeated by a brake bleed when using a Mini VCI dongle (it succeeded at last on my fifth or sixth try), but a later one I tried with a Tactrix dongle went without a hitch.

    But I think these details are quite different between Gen 2 and Gen 3.
     
  3. dolj

    dolj Senior Member

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    Just to clarify, you are pressing the power switch twice with your foot OFF the brake to get to IG-ON?



    Prius power cycle modes:
    Mode
    Action​
    1 ACC
    • With the car in OFF; and the foot OFF the brake; press the start button once.
    2 IG-ON
    • If the car is in OFF; with the foot OFF the brake; press the start button twice.
    • If the car is in ACC mode; with the foot still OFF the brake; press the start button once more.
    3 READY
    • With foot ON the brake; press the START button once; this can be done when the car is in any other mode.
    4 OFF
    • If the car is in READY; press the START button once; it does not matter whether the foot is on or off the brake.
    • If the car is in ACC mode; with the foot OFF the brake; press the start button twice.
    • If the car is in IG-ON mode; with the foot OFF the brake; press the start button once.
     
  4. SFO

    SFO Senior Member

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    Which version of techstream is being used?
     
  5. mr_guy_mann

    mr_guy_mann Senior Member

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    Do you have the parking brake applied? Otherwise I might think that the quality of the usb adapter is causing a problem.

    Posted via the PriusChat mobile app.
     
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  6. Douglas88

    Douglas88 Junior Member

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    Yes that is correct. IG-ON mode.... by pressing ig two time w foot off brake at all times.
     
  7. Douglas88

    Douglas88 Junior Member

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    16.00.017
     
  8. Douglas88

    Douglas88 Junior Member

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    NO I did not have parking brake applied. Perhaps this is the issue. I will try that tonight.
     
  9. Douglas88

    Douglas88 Junior Member

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    Thank you, Perhaps this is the cause, Just not a good enough dongle. That would at least mean it is not my car, or a problem I am doing. I have noticed that I do not have "health check" buttons or "utility" buttons or menus in my Mini VCI techstream app. I think others do have that, some on the prius chat. I find it limits my ability to do many things, like turn off the auto door locks feature, or seem to be able to add a new key fob W this tech stream. It is version 16.00.017, running with the mini VCI version 1.48, if the advertisement was accurate. I noticed a VCI with version 2.04 for more cost, dont know if that might help. I wander if that it why I also do not have the health check and utility buttons...that it sounds like others have?
     
  10. ChapmanF

    ChapmanF Senior Member

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    I think the absence of menu options probably has more to do with the version of the Techstream software itself, and the skill of whichever hackers mauled it to make it (mostly) work without a paid-up activation key.

    In my experience, the capabilities and quality of the dongle can have effects on which Techstream operations to which of the car's ECUs produce errors or actually work, but a dongle change isn't likely to change the basic buttons and menu options Techstream shows you.
     
  11. Douglas88

    Douglas88 Junior Member

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    This WAS the issue. I got it to work by applying the parking brake, and then went on to havesuccess in resolving all the brake issues. Thank you very much!!! Sorry it took me so long to get back with the outcome.
     
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  12. mr_guy_mann

    mr_guy_mann Senior Member

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    You're welcome. Thank you for updating your post. It's less likely that someone will resurrect this thread 5 years from now asking - "I've got the EXACT same problem- what was the fix?"