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Thread: 4l80e swap, 02 Yukon, Limp Mode, no DTC, repinned, segment swapped, I'm stumped

  1. #1
    Tuner in Training
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    Nov 2014
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    4l80e swap, 02 Yukon, Limp Mode, no DTC, repinned, segment swapped, I'm stumped

    As the title says, I have an 02 Yukon where I'm trying to swap the 4l60e with a 4l80e.

    I'm stumped.

    4l80e was rebuilt entirely. New everything including solenoids. Internal dual feed mod, Sonnax Sure Cure AFL kit, pump drilled to prevent seal push out.

    Attached are the files I used. Stock, Segment Source and Current file starting with Read_2_Seg...hpt

    Can someone review my Read_2_....hpt tune?

    VSS in front and rear both read seemingly proper values.

    I've run diagnostics on the solenoids and here are the results.

    ---------------
    12v verified at pin E on PCM to trans connector.

    1-2 solenoid 20ohm, A, OK, clicks with 12v

    2-3 solenoid 21ohm, B, OK, clicks with 12v

    PCS, pressure control solenoid 4ohm, Force Motor, OK

    TCC solenoid 10ohm, OK

    Temp sensor 4k ohm, OK
    ---------------

    On stands I...

    Tried to force shifting like so, stuck in 2nd:


    Tried to drop to first by playing with 1-2(A) and 2-3(B) Solenoids. ON-OFF combo should drop to first, right? No dice! Calculated ratio confirms no shift and still in 2nd.


    I even supplied 12v to the trans and forced 1-2(A) to ground and no 1st gear or change of any sort.

    Here are the DTC I've enabled on first MIL: DTCs (P0500, P0608, P0700 to P0724, P0740 to P0757, and P1504)

    I could really use some input. I'm stuck. This is my first swap ever and I've tried to do my homework!

    Thanks,
    -Eric
    Last edited by tgui; 01-09-2016 at 05:03 PM.

  2. #2
    Tuner in Training
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    I verified the input VSS is working. I read that if it wasn't then the trans goes into limp mode. I disconnected it, got 0 rpm on input VSS log and caught a DTC immediately.


  3. #3
    Tuner in Training
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    I also commanded shifts again.

    A-B Solenoids
    - 1st, clicks heard. ON-OFF
    - 2nd, no clicks, OK, OFF OFF
    - 3rd, clicks heard OFF-ON
    - 4th, clicks hears, ON-ON

  4. #4
    Tuner in Training
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    I'll not ask too much, but does someone have any input? I'll be doing a pressure test soon.