Echo read timeout ?

  • curejr


    I'm trying to use freediag 0.3 to read my car dtc and it doesn't work.
    When running the scan with the debug active I can see the error:

    "slowinit fd 4 echo read timeout"

    I do understand the meaning of this error but I don't know how to fix it.
    My car is an Acura Integra 2001 and I'm running the software on Knoppix 5.1.1.
    I can't install linux on the laptop that I'm using (it's not mine) so I
    found this version of linux which is running on a CD.  I'm able to
    compile and run the software but like I wrote I'm keep having the same
    error while running the scan command.

    First I thought the problem was the device I builded (Jeff's OBD-II ISO 9141)
    but according to my tests the device seems to be working properly.

    I did three tests to confirm that :

    (1) Multimeter test

    I connected a 12V source to the device instead of connecting it to my car
    and I verified the signals.  While running the scan command I confirmed
    that there was a signal on TXD and RXD.  So this confirmed me that the
    bits sent on TXD were sent back on RXD.

    (2) Echo test

    Again I connected a 12V source to the device instead of connecting it to
    my car and I sent data to the device using a windows program (one that I
    was able to control DTR line).  Every bytes sent were echoed back.

    (3) Andy Whittaker test software

    Using Andy test software I've been able to wake up the ECU (send 0x33
    and receive 0x55).  One thing that I didn't figured out yet is that
    I had to use the "K and L Init" function instead of the "Normal Init".
    I verified and my car doesn't have a L line so it's has nothing to do
    with the L line.  It could have been the problem since I know some ECU
    need to be wake up on L Line but it's not the case for my car.

    I'm using the default freediag settings which I think are the good
    one for my car and my device.  Now I don't know what I can do more
    to make it work.  I've seen in a thread that freediag has been
    written to run on RedHat but since I can't install it on my laptop
    I have to use Knoppix.  I don't know if Knoppix could be the root
    cause of my problem.

    Can someone help me ?


    • curejr

      I finally found the problem.  I don't know if it's a bug or a feature :) but sending and receiving one byte at 5 bauds using Knoppix require 10 seconds instead of 2.  I don't know why this delay (I've been told that it might be related with the serial driver) but since the timing is very crutial the result of this unexpected delay was the "echo read timeout" error.  So to make the software works I had to fix this issue and others because there was other things that were not working as expected.  After some code changes I've been able to make it works and now I can read the DTC on my car.  As soon as I have time I'll post the modifications I've made so it might be useful for someone else.

  • soyo

    Hi curejr,

    I have same problem as yours. If you have new codes, please tell me.


  • CSB

    soyoeml, you should at least be using the latest code in CVS; freediag-0.3 is deprecated. You will of course have to compile from source.
    If you have further problems, just post error messages; I'll see what can be done.

  • soyo

    I'm using the newest codes in cvs. I have already fixed this. Thank you.

  • CSB

    soyoeml, I'm glad you're spending time doing a bit of debugging - could you please eventually post a patchfile of all your fixes ? That way it can all go to CVS.

  • soyo

    I can put my patchfile. But how to submit codes? Could I be a developer?