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Damaged OBD2?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SQST, May 13, 2024.

  1. SQST

    SQST New Member

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    Hello everyone,

    My mom took her 2004 Prius for an inspection in Colorado, but was turned away due to an issue with the OBD2 connection. I used a Bluetooth dongle with Torque PRO to check, and initially, everything seemed fine.

    She has been driving around with a Bluetooth dongle in the OBD2 port for an extended period, and I'm concerned that it might have damaged the ECU, leading to read errors with the inspection equipment. I've already removed the dongle.

    She tried multiple stations, but the problem persisted. I'm considering the possibility that the constant use of a low-quality dongle may have compromised a signal line. Replacing the ECU seems viable since they are available inexpensively on eBay, and it appears that the VIN is not integral to the ECU, allowing for a straightforward swap.

    I don't have the wiring diagrams, so I'm unsure whether the OBD2 connection is direct to the ECU or if there are other modules involved. I would appreciate any guidance on this.

    Next, I plan to use a scope to check for signal issues at the connector or other mechanical problems that the dongle might not have affected. Although I initially dismissed an odd reading as a settings issue in Torque, the problem reoccurred after adjustments.

    Thanks in advance for any advice you can provide before I proceed.

    Alex
     
  2. Tombukt2

    Tombukt2 Senior Member

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    There is a fuse that's involved with the OBD2 port some of these early Bluetooth things and what have you weren't bi-directional but I don't think that would generally cause any problems My wife has a 2010 solder roof car that she left the Bluetooth dongle in for $300,000 miles while she drove it never really caused any problems that I know of although there was a month where I could not get the Toyota software through the xhorse cable. To connect to the car and then all of a sudden it was working again this is not a car that I see very regularly but that was that I'm not really sure how I'm seeing the Bluetooth dongle could damage the plug assembly and or necessarily the computer that it communicates with but anything is possible of course there be people along shortly that live there lives in the electronics of this particular vehicle that will shed some light on some things there are some threads here about this exact or similar issue with the OBD2 port or receptacle.
     
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  3. dolj

    dolj Senior Member

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    What are 300,000 dollar miles? Is this some kind of US folklore thing?
     
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    My first thought is that you could have damaged terminals in the OBD2 connector. Often, the state inspection cable can be "fussy" about having the terminals be "just right".

    On the other hand, cheap dongles can have oversized pins that can still make contact even if the OBD terminals are tweaked some.

    You can test by getting a correct male terminal to see if the OBD port female terminal fit. (AFAIK, terminals like these should work) The test terminal should fit "snuggly" and take a little bit of effort to pull out.


    If this is the case, then it's possible (but not easy) to remove the tweaked terminal from the OBD port and use a pin to carefully bend the internal spring contact back into shape. Screenshot_20240515-212554.jpeg

    Posted via the PriusChat mobile app.
     
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  5. mr_guy_mann

    mr_guy_mann Senior Member

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    It's a Tom thing.

    Posted via the PriusChat mobile app.
     
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  6. rjparker

    rjparker Tu Humilde Sirviente

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    That would be Mendel masquerading as Neo in the Matrix’s gen3 hybrid electronics.