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cable not working? diagnostic procedure

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  • cable not working? diagnostic procedure


    I recently bought an OBD2 to USB cable which is supposed to work with my car. I couldn't manage to get it working though. I am using Ubuntu 9.10. Before I start doing "esoteric" testing, I'd like to know better what the "diagnostic procedure" is. I tried -b 38400 and -b 9600. When I connect the cable, it automatically creates a /dev/ttyUSBX device. I'm running obdgpslogger and obdgui as root, but I also tried changing the permissions of the device to 777 and running as a regular user (the device is created as property of dialout:root)

    I read you think the Ubuntu 9.10 FTDI driver is quite broken. How can I determine if this is the problem? If I were to switch to a different version... should I go from 8.04 or 10.04?

    My project: double indash, Golf IV

  • #2
    What exactly is the device you bought? OBD GPS Logger relies on elm327 protocol to work and there are some devices out there that don't have that, it seems.

    The way to test it is by using screen or similar. Try a few likely baudrates [9600, 38400, 115200] thus:
    screen /dev/ttyUSB0 38400
    Once screen opens, hit enter a couple times. If you see ">", that's good, that's the prompt. Your two base commands from here are "ATZ" which is "reset" and should show you a device ID, and/or "0100" which is your base "ask the car *something*"

    To exit screen, hit ctrl-a then k.

    If you see it working but then after a while things seem to stop working, or they stop working very soon, that's exactly the bug in 9.10 [although supposedly it's now fixed].

    Gary (-;
    OBDGPSLogger, for logging OBDII and/or GPS data
    OBDSim, an OBDII/ELM327 software simulator
    mp3car forums: obdgpslogger, obdsim


    • #3
      Thanks for the quick reply. I'll come down to the car now with my laptop to try what you said.

      Hey, one suggestion: why there's no "paypal donate" in your project page? Let us pay you coffee!
      My project: double indash, Golf IV