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2016 Prius Post Accident Fault Codes

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by EK26, Jan 14, 2018.

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  1. EK26

    EK26 New Member

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    I recently purchased a salvaged 2016 Prius which was rear ended, the damage was only to the rear bumper and lift-gate; all airbags are intact, the car turns on and drives. I'm currently in the process of restoring the vehicle to keep for myself and am having some trouble with the following fault codes:

    Airbags : B165A
    ABS : C1425
    Pre-collision system 2 : C1A50
    Occupant detection : B1785
    Lane-keeping assist 2 : C1A50

    I used Carista to obtain the fault codes and when I try to reset them they come back. Would anyone know where I could lookup the meaning of the fault codes, or how to reset them? Are these ones the dealer can only clear after running some maintenance, or diagnostic, tests?

    Thank you in advance! Really appreciate the help!

    Screenshot_2018-01-13-21-22-30.png
     
    #1 EK26, Jan 14, 2018
  2. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    #2 Prodigyplace, Jan 14, 2018
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  3. kithmo

    kithmo Couch Potato

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    I may be wrong, but I suspect that because they are all safety related codes they may be dealer (or techstream) reset only.
    Alternatively it may be that some sensors need replacing before the codes can be reset.
     
    #3 kithmo, Jan 14, 2018
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  4. bisco

    bisco cookie crumbler

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    congrats and welcome!

    get yourself mini vci and subscribe to toyota tech info .com for service manual.
     
    #4 bisco, Jan 14, 2018
  5. Elektroingenieur

    Elektroingenieur Senior Member

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    As @bisco kindly suggests, you should refer to Toyota’s Repair Manual, available by subscription to techinfo.toyota.com, which has general information (“How To Troubleshoot ECU Controlled Systems”) and a step-by-step procedure for each diagnostic trouble code.

    Your local libraries (Seattle, King County) also sponsor access to the ChiltonLibrary service, where you’ll find most of the same text and illustrations, but not the Electrical Wiring Diagram or New Car Features books.
    I don’t know of any dealer-only repair or maintenance tasks on Toyota vehicles; see my previous posting for more about this. There are, however, some utility and active test capabilities of the Toyota Techstream diagnostic software, which is also available from techinfo.toyota.com, that makers of third-party programs like Carista may not have chosen to license from Toyota.

    To use Techstream, you need the software and a compatible J2534 vehicle interface module, such as the MongoosePro MFC2 in the official Techstream Lite kit or a Tactrix Openport 2.0.
    B165A and C1A50 are secondhand information—one ECU saying it’s heard from another ECU that there was a problem—and will probably stay cleared once the underlying trouble is fixed.

    The remaining two codes, C1425: Open in Stop Switch Circuit and B1785: Front Occupant Classification Sensor LH Collision Detection, are important to diagnose and repair. For B1785, the manual suggests zero point calibration with Techstream first; if that doesn’t work, you’re supposed to replace the front seat adjuster assembly RH, not the occupant detection ECU.
     
    #5 Elektroingenieur, Jan 14, 2018
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  6. EK26

    EK26 New Member

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    Thank you all for the prompt feedback! I really appreciate the help!
     
    #6 EK26, Jan 15, 2018
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  7. padroo

    padroo Senior Member

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    B165A/32 occupant detection sensor zone point calibration incomplete.

    C1A50 Brake system malfunction.
     
    #7 padroo, Jan 15, 2018
    Last edited: Jan 15, 2018
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  8. EK26

    EK26 New Member

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    UPDATE : After plugging in the bumper tail lights, all connectors unplugged previously since bumper was off, 3 out of the 5 codes have disappeared and the only current active codes are :

    Airbags : B165A
    Occupant detection : B1785

    Thank you @Elektroingenieur and @padroo, your input plus some googling helped me clear those three faults.
     

    Attached Files:

    #8 EK26, Jan 15, 2018
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  9. padroo

    padroo Senior Member

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    Code B165A.jpg
     

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    #9 padroo, Jan 15, 2018
  10. padroo

    padroo Senior Member

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    Code 1785.jpg Code 1785.jpg Pay attention to the black arrow.
     
    #10 padroo, Jan 15, 2018
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