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Thread: E67 ECU (LE5 Ecotec) tach signal

  1. #1
    Tuner in Training
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    E67 ECU (LE5 Ecotec) tach signal

    I see on the forums some people have had success adding a tach signal to the E67 on V8 engines, but is there a way to add (or turn on) the tach output on the LE5 (I use a 2007 HHR as my initial tune)?

    I have them installed in a couple Dune Buggies, and it sure would be nice NOT to have to buy a $100 Tach adapter for each one we do, if I could just swap around some settings in HPTuners, and run a wire.. that would be fantastic..

    am I nursing a pipe dream here... or can it be done??

    what settings? and what pinout on what connector if someone already knows this info.

    Thanks in advance

    Jeff

  2. #2
    Advanced Tuner Shrek's Avatar
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    I never work on anything with less than 8 cylinders ... so the following should be considered as general information.

    HHR initially used the E67 ECM, but transitioned to the E37 ECM. Your 2007 E67 should be Service Number 12605843. On V8 calibrations (CTS-V / Trailblazer / etc.) the Tach output is on C1 (blue) pin 25. You will need to change the output type from "Serial" to "Crank", and configure the pulses appropriately - no idea on an HHR.

    You may also need to wire a Tach pull-up circuit to obtain a usable output signal.

  3. #3
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    Yes, we are using 12605843's for sure..

    I found the posts regarding the V8's doing this with pin 25 on the blue connector, but was hoping someone had tried to do it on the 4cyl vehicles.

    is there any info out there about wiring a tach pull-up circuit?

    I guess I will just have to try it then!

  4. #4
    Advanced Tuner Shrek's Avatar
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    Quote Originally Posted by hefe33 View Post
    ... is there any info out there about wiring a tach pull-up circuit? ...
    Google search of "tach pull up circuit" or "tach pull up resistor" ... will give you lots to read ...

  5. #5
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    yep I did that..

    looks pretty simple..

    I guess I will try it and report back... wish me luck

    I think the hardest part is going to be putting a wire in the connector where there isn't one now (pin 25 is empty)

  6. #6
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    I hate to bring back an old thread, but I myself am looking for a pinout on the E67 2.4L LE5 ECM for a tach signal. Could you report on how you did it and what you did, along with your results? Thanks in advance!!!

  7. #7
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    sorry man... this is something I was meaning to get back to, and never did..

    the pull up resistor seems like a solid lead though.. I'd research that and see if hooking up pin 25 on the blue connector does the trick

  8. #8
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    Quote Originally Posted by hefe33 View Post
    sorry man... this is something I was meaning to get back to, and never did..

    the pull up resistor seems like a solid lead though.. I'd research that and see if hooking up pin 25 on the blue connector does the trick


    Pin J1-25 is the tach output,J1-24 is the pullup resistor for it. Just tie the 2 pins together and go to tach input. This works for all of the E67 controllers. Steve