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How to Read ABS/TCCM/PCM Codes Using a Terminal OBDii Interface

Discussion in 'Article Submissions' started by SAR85, Sep 18, 2012.

  1. SAR85

    SAR85 Well-Known Member

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    Summary: How to Read ABS/TCCM/PCM Codes Using a Terminal OBDii Interface
    Difficulty: Easy (mechanically), but medium computer skills are required
    Estimated Time: 30 minutes for first time, 10 minutes subsequent times
    Tools Required: Personal computer with Windows 7 (or ability to adapt instructions for use with other operating system), Bluetooth OBDii adapter (or wired adapter again with ability to adapt instructions), wOBD software (free online)


    This article will explain how to use a PC running Windows 7 with a Bluetooth OBDii adapter in order to communicate with the PCM and other modules (TCCM, ABS, and airbag). The first section outlines how to set up your computer to communicate with the vehicle and the second section outlines the specific commands involved in retrieving DTCs. This information is applicable to other computer platforms and hardwired OBDii interfaces as well, but this will require adaptation. Some members may have access to software that has the same functionality as that described here. The instructions in Section 2 below are still applicable in using this other software.

    Note: This article will work for older GM models that use the J1850 VPW OBDii protocol. This information may apply to newer vehicles that use the CAN protocol, but the headers will need to be modified. I do not have a CAN vehicle and do not know the headers that would need to be used. If someone posts them I (or a mod) can add that information to the article and make this complete even for the newer models.


    Setting Up Your Computer and OBDii Adapter

    1. Download wOBD from OBD2 Software (this is free software). Install the application to your computer.

    2. Pair your computer with your Bluetooth OBDii adapter. This process will vary depending on your computer and Bluetooth software. It will require you to have the adapter plugged in to the OBDii port in the vehicle and your computer to be in range of the adapter.

    3. After pairing, go to Bluetooth settings in the control panel. The window should look something like this:


    4. Click on the “COM Ports” tab, then click the “Add…” button.

    5. Choose an “Outgoing” connection, choose your Bluetooth OBDii adapter to use, then press “OK”.


    6. On the Bluetooth settings window, note the COM port assigned to your Bluetooth adapter (COM4 in the example image below).


    7. Open wOBD and select the COM port corresponding to your Bluetooth adapter (again, COM4 in this example).


    8. Click on the “wOBD2 Explorer” button.


    9. Select the options that you prefer (I prefer to keep all lines showing, which is not the default option).

    10. When ready, press the “Open OBD” button. Commands will be typed into the text box near the bottom of the dialog, and are sent by pressing the “Send Command” button. Commands will be discussed below.

    [HR][/HR]

    Communicating With Your Vehicle

    1. To read DTCs, send the following commands:
    2. Send one of the following commands:
    2. The response should should be similar to: "6C F1 XX 59 ZZ ZZ YY", where XX is the same as the code for the module as above, ZZ ZZ represents the desired DTC, and YY can be ignored.

    3. To interpret the DTC, take the first number and convert it as follows:

    View attachment 22899
    Image courtesy of: Elm Electronics

    4. Then, add the next three numbers to complete the DTC. As an example, if the message received is “6C F1 10 59 01 72 17”, the numbers of note would be “01 72”. The 0 converts to a P0 followed by 172, which is combined to be code P0172.

    5. To clear codes, send the following commands:
    Response should be “6C F1 XX 54”.

    Note: codes can only be cleared after they have been requested as described above. A clear command cannot be sent before requesting codes.
     

    Attached Files: Download all post attachments

    dvldrmmr likes this.
  2. AtlWrk

    AtlWrk Well-Known Member

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    Thanks for this! :thumbsup::thumbsup:Saved me from having to go to a dealer to investigate my stabilitrac/traction control light. I even found some codes for a few things for which I had no indication there was a problem.

    One thing that helped me out was using "FE" for XX in this step:
    ATSH 6C XX F1 (replace XX with 28 for ABS, 40 for the BCM, 10 for PCM 58 for air bag, or F1 for TCCM)

    This tells all modules to respond. While this kept resulting in "buffer full" I did get a dozen or so positive responses from a bunch of other modules (29, A1, etc.) which I then polled individually. For those using more robust interfaces (i.e. STN1100 based modules) this may be a complete shortcut.
     
  3. Opus62

    Opus62 New Member

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    Thanx! I tried this with my 1999 Buck Park Avenue and it worked flawlessly! I have an ELM327 Bluetooth interface and I used Android software that I found for my tablet [much easier than lugging my laptop out to my vehicles].
    I went over to my 2005 Tahoe to diagnose a 4wd problem and I got some odd responses. CAN-BUS perhaps? This is what I entered and the responses right below each line:

    >ATH1
    OK

    >ATSH 6C 58 F1
    OK

    >19 FF FF C0
    6C F1 58 7F 19 FF FF C0 12 26 <-this is the first odd response


    >ATSH 6C F1 F1
    OK

    >19 FF FF CO
    NO DATA <- this is the second odd response

    It seems as if I can communicate with with the truck systems but we appear to be speaking a different language, to some degree.

    Has anybody been able to get TCCM codes from a 2005 Tahoe?
     
  4. Chris JW

    Chris JW Well-Known Member

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    couple things
    I am no expert on this but i noticed

    "19 FF FF C0" code you used

    "19 FF FF 00 (for all codes)" code article uses

    don’t know if this is relevant for sure, but hope it helps

    and

    where did you get the android software???? or whats it called?
    A link would be great if you have it handy
     
  5. Obi Juan Kenobi

    Obi Juan Kenobi Member

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    Thanks for this post. I was wondering if it is possible to cycle an ABS pump with this sort of device? If so , what is the command? It's not for my Trailblazer but for my 2004 Silverado. Thanks.
     
  6. Ekaking1

    Ekaking1 New Member

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    Hi,

    I am getting BUS INIT: ...ERROR after using ATSH 6C F1 F1 for my TCCM and any of
    19 D2 FF 00 (for current and pending codes)
    19 C2 FF 00 (for current codes)
    19 FF FF 00 (for all codes)

    Any Ideas?
    My car is a Chevy Trailblazer 02
     
  7. AtlWrk

    AtlWrk Well-Known Member

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    The "F1" for the TCCM module is suspicious. F1-FD module IDs are supposed to be reserved for diagnostic tools.

    If it is in fact, correct try ATSH 6C F1 F2 instead.
     
  8. Trey73

    Trey73 New Member

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    Yes the second set of characters should be the address of the Scan tool "A1" and the third set should be the addresss of the TCCM "F1".

    >ATH1
    should respond with "ok"

    >ATSH 6C A1 F1
    should respond with "ok"

    then enter your query....
    19 C2 ff 00

    it should spit out pending codes.

    When it returns the information the F1 and A1 will reverse positions, the fourth set of characters would be 59 (you queried "19" and it adds 40 to that number when it returns the info), the fifth and sixth pair are what you will use to lookup the code.

    If you searchg for ALL stored codes (current, pending, historical) using "19 ff ff 00", the seventh set of characters will tell you whether the code is still a problem (11 or greater) or it will be "1" if the DTC has been corrected.

    I also saw that in one of the post above someone substituted a letter O instead of zero. Because it is hex, it does not use the letter O, they will always be zeros.

    I used the free android app ELM Basic, and it is AWESOME, simple, pain free, and doesn't have ads or need a bunch of suspicious permissions. Just figure out how to make a screenshot of the results ahead of time, it will help!

    I hope this helps someone,
    -Irish
     
  9. primerchevy

    primerchevy New Member

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    Thanks for the great info! I was able to communicate successfully with the TCCM in my truck up until i entered "19 FF FF 00" for all codes then i got the message "CAN ERROR". Im using ELM Basic, anyone else have this problem or know what i should do differently?
     
  10. primerchevy

    primerchevy New Member

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    Ok after some research I've realized that Ii was only communicating with the elm327 and not actually getting through to the tccm. I think I the address is wrong so I tried the above suggestion to use FE to request all modules to try to determine the tccm address but still returned the can error message.
     
  11. jsheahawk

    jsheahawk Well-Known Member

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    I had the ABS light pop on, and I thought I'd give this a try. I'm using ELM Basic. I pulled my known airbag codes (swapped seats, no side curtain bags), but it gives me "NO DATA" when I try to pull ABS codes. My ABS light is actively lit.

    Here are my commands:
    ATH1
    "OK"
    ATSH 6C 28 F1
    "OK"
    19 C2 FF 00
    "NO DATA"
     
  12. Jason Denniston

    Jason Denniston New Member

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    I have a 2008 Impala, air bag and abs lights on, and I get the same "no data" response.
     
  13. Mooseman

    Mooseman Moderator

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    You are not going to get a response from the OP since he hasn't been on since Feb.2015.

    And this is a truck forum. Commands may be different for cars.
     
  14. Jason Denniston

    Jason Denniston New Member

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    Thanks for the heads up. That might explain why it worked on my Rainier, and not the Impala.
     

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