Results 1 to 5 of 5

Thread: Help with my VDO speedometer in my Fiero

  1. #1
    Junior Member
    Join Date
    Jul 2011
    Location
    Geneva
    Posts
    12

    Help with my VDO speedometer in my Fiero

    Hi there.
    Has anyone here installed a VDO speedometer into their Fiero.

    I recently completely changed my 88GT interior. I installed the pisa eurodash. The end result is amazing but I keep geetting the code 24 coming up.
    I calibrated the VDO guage by entering 4000PPM into the gauge and the speedo seems to work fine.

    However the Cruise control no longer works (it worked fine before) and I don't think I have touched anything on the cruise control system. Also the car often stalls when I am driving and put the clutch in.

    Have I entered the wrong number to calibrate? I have read the the signal going to the ECM should be 2000 and that the standard Fiero guage divides the 4000PPM signal from the VSS by 2.

    I have not touched the VSS (it is the standard one that was in place before I changed the interior)

    Can anyone help me?

    Regards,

    David

  2. #2
    The ECM needs to see your speed too. That same signal enters your cruise control module too.
    It looks like you may need to connect your old speedo head and hide it in the dash. It seems to be doing a digital signal in the speedo head and sending that signal out in a brown wire #437. It connects to pin C2 #2 on the ECM.

  3. #3
    Senior Member rodrieguz's Avatar
    Join Date
    Aug 2003
    Posts
    270
    The circuit board that plugs into the back of the fiero gauge cluster is the only way to get the speedily to work correctly

  4. #4
    Junior Member
    Join Date
    Jul 2011
    Location
    Geneva
    Posts
    12
    ok. Thanks for that info.

    Spent last night re-installing the orginal speedo in parralel with the new one and hiding it in the dash. Not had the chance to test it yet. will let you know how I get on.

    Does anyone know why the ECM and cruise control is like this?. It seems crazy to design a car where the VSS and speedo work on one PPM (4000) and then have the ECM and cruise control working on a different PPM (2000).

  5. #5
    Junior Member
    Join Date
    Jul 2011
    Location
    Geneva
    Posts
    12
    I managed to take the car out and test it this weekend and everything worked great. I had to sort out a slight problem with earths, but once that was done, everthing worked. The cruise control was fine, no warning light and the engine did not stall when I put the clutch in.

    I took it up into the mountains for a proper test.

    Thanks for everyones help on this. Greatly appreciated.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •