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Thread: 4l80 swap with frost harness without segment swap

  1. #1
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    Default 4l80 swap with frost harness without segment swap

    So i installed my 4l80 installed the frost subharness and the directions seem to be written for a hp unit has anybody used there harness that maybe able to help im stuck. I had tunes through my purchaser of efilive but there supplied 4l80 tune has resulted in a 1870 code and no responce from them on what to do or actually no responce at all. Ive put about 50-60 miles on it and as of now have stopped driving it for fear of burning either the trans or triple disc converter up. Any help greatly appreciated thanks in advance

  2. #2
    Joe (Moderator) joecar's Avatar
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    I think the instructions say to disable DTC P1870... can you post the instructions here.

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    Max out Trans Component Diagnostic Enable Temp (under Trans Diag in HPTuners, P1870)
    *Set P0717 to No Error Reported (4l70 to 80 swap only)
    *Some vehicles require P0741 set to No Error Reported
    *Must tune 4l80 shift points (different gearing)
    *PRNDL Switch must be the same as what came in the vehicle originally (for DBC swaps use F-body base to eliminate PRNDL)
    *Leave front speed sensor on the 80 unplugged

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    Ive spoken with him he said he dont use efi suggested i send him my pcm for him to correct, I saw a old forum where someone had said to change gear ratios to compensate for the lack of efi's ability to do #1 but i guess i was hoping to find someone who could share there experience with me

  5. #5
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by james workman View Post
    Max out Trans Component Diagnostic Enable Temp (under Trans Diag in HPTuners, P1870)
    I think this might be E0803/4, set E0803 to min and E0804 to max.

    *Set P0717 to No Error Reported (4l70 to 80 swap only)
    set C6001 P0717 to Not-Reported.

    *Some vehicles require P0741 set to No Error Reported
    set C6001 P0741 to Not Reported.

    *Must tune 4l80 shift points (different gearing)
    You have to set the gear ratios and edit the Shift at VSS/RPM tables, you gotta know how to do this.

    *PRNDL Switch must be the same as what came in the vehicle originally (for DBC swaps use F-body base to eliminate PRNDL)
    *Leave front speed sensor on the 80 unplugged

  6. #6
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by james workman View Post
    Ive spoken with him he said he dont use efi suggested i send him my pcm for him to correct, I saw a old forum where someone had said to change gear ratios to compensate for the lack of efi's ability to do #1 but i guess i was hoping to find someone who could share there experience with me
    You would have to change the gear ratios and MPH shift points anyway to make it work properly.

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    Thanks i was just reading a old tread from like 2006 that showed how to make adjustments on shift times, firmness, ect. But not much was said about tcc apply Ive seen someone else had suggesting changing min.tcc to 98% any thought on it.
    And then there was my converter supplier he had said it was a bad idea to operate an 80 on a 60 segment said it would end up burning up the trans and converter any thoughts on that? or any knowledge of anyone doing it thanks I've seen alot of posts where you have offered advice or suggestions and its appreciated thank you

  8. #8
    Joe (Moderator) joecar's Avatar
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    Yes, change TCC Min PWM to 98%, this would give a quicker lockup, and would avoid partial lockup (i.e. dragging).

    There have been various people on LS1tech that are running a 4L80E on the 4L60E segment, they are not having any problem with the TCC...
    it would be a bad idea if PCM's TCC PWM signal was used to drive the 4L80E's TCC PWM wire, this has to be avoided...
    your harness should be driving it from the PCM's TCC ON/OFF signal.
    see here for more info: 4L80E-Reference-Material~post#12



  9. #9
    Joe (Moderator) joecar's Avatar
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    Also, your harness should have a relay in it to invert the sense of the 2-3 Shift Solenoid B signal.

  10. #10
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    So it would of been cheaper and about tbe same amount of work changing the os and repin and front iss harness ( still got the one i intended to use) instead of the harness. Damn wish I would of known that before now, thanks I really appreciate the information

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