Random Codes ON after Dongle Insertion

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by PriuSocal, May 19, 2026 at 12:36 AM.

  1. PriuSocal

    PriuSocal Member

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    I purchased a Gearwrench OBD2 Dongle reader and when I tried inserting it into the OBD port It felt as something was impeding it from seating in. I wiggled it a bit (did not yank or force it) to seat it and then the YTOD came on and the “Check Hybrid System” came on BUT NO CEL. I immediately removed the dongle and turned the car off.

    I then hooked up my BlueDriver to it to see what had happen and had the following codes:

    - U0073 Control Module Communication Bus “A” Off
    - U0123 Lost Communication w/ Vehicle Dynamics Control Module
    - U0124 Lost Communication w/ Brake System Control Module
    - U0126 Lost Communication w/ Steering Angle Sensor Module
    - U0293 Lost Communication w/ A/C Control Module
    - U0129 Lost Communication w/ Hybrid Powertrain Control Module

    I went ahead and deleted those codes only and cleared Battery codes w/ Dr.Prius and the dash went back to clear w/ no YTOD. I drove the car and nothing different, runs, drives and brakes perfectly but i went ahead and used TechStream to do a Health Check and the above codes show up (see screenshot as well). I did do a search on here and found some people who had experienced same codes but they had issues with the ABS and FAIL SAFE activating which mine does NOT have so I am almost positive the GW OBD2 dongle caused this but now wondering how to delete all this without doing a whole ECU reset / Clear codes.

    IMG_3949.jpg

    Any help will be greatly appreciated.
     
    #1 PriuSocal, May 19, 2026 at 12:36 AM
    Last edited: May 19, 2026 at 12:46 AM
  2. Tombukt2

    Tombukt2 Senior Member

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    I'd clear that U stuff . Heck the dongle pins ? I. Using same the long GW tool not the short 40 dollar unit .this is longer same color and 140bux I've used my on about 74 vehicles with no hiccups. Can even deal with electrics no kidding .can scan BYD and rivian and Mercedes .
     
    #2 Tombukt2, May 19, 2026 at 8:44 AM
  3. Tombukt2

    Tombukt2 Senior Member

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    This GW long thing has a hundred updates weekly .
     
    #3 Tombukt2, May 19, 2026 at 8:44 AM
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  4. PriuSocal

    PriuSocal Member

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    No, I got the small $40 one to gift to my father in law but wanted to check it out first and this happen.
     
    #4 PriuSocal, May 19, 2026 at 6:10 PM
  5. Tombukt2

    Tombukt2 Senior Member

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    The long one works very well I've had no trouble with it the short one looks like it should work similarly other than missing some maintenance features it's same!
     
    #5 Tombukt2, May 19, 2026 at 6:49 PM
  6. PriuSocal

    PriuSocal Member

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    I dont trust hooking that back up into my car
     
    #6 PriuSocal, May 19, 2026 at 8:43 PM
  7. Tombukt2

    Tombukt2 Senior Member

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    Yeah that's really weird because the software they're running is actually quite good but maybe something wrong with that one . Try some other car .
     
    #7 Tombukt2, May 19, 2026 at 8:52 PM
  8. PriuSocal

    PriuSocal Member

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    Feels cheap and doesnt sit right int he obd port.
     
    #8 PriuSocal, May 19, 2026 at 11:10 PM
  9. ChapmanF

    ChapmanF Senior Member

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    That could be the whole story right there. I had a little homebrew dongle thing that worked great for a couple years, then started making a flood of Uxxxx communication codes any time it was plugged in. The J1962 connector I had used had no plating on the pins.

    I replaced that connector with one with gold-plated pins, never another issue.
     
    #9 ChapmanF, May 19, 2026 at 11:17 PM
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  10. PriuSocal

    PriuSocal Member

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    A J1962 with gold plated pins? Ill have to check the VCI I have for techstream to see if its gold plated but works great.
     
    #10 PriuSocal, May 20, 2026 at 2:56 AM
  11. Tombukt2

    Tombukt2 Senior Member

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    Yeah but when you into the end of the yellow unit it all looks straight hmm interesting. I'd get replacement GW seems to not fek around . As in warranty the 800 number
     
    #11 Tombukt2, May 20, 2026 at 8:19 AM
  12. ChapmanF

    ChapmanF Senior Member

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    Even a nice shiny tin or silver plate like you normally see on connectors is probably fine. Like I said, the connector I had at first was some cheap nice person junk, didn't look like they plated those pins with anything.
     
    #12 ChapmanF, May 20, 2026 at 10:48 AM
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