Results 1 to 7 of 7

Thread: Early model 6L80e gear hunting in conversions problems

  1. #1
    Member
    Join Date
    Sep 2010
    Posts
    74

    Default Early model 6L80e gear hunting in conversions problems

    Hi Guys, Ive come across a curly one here and interested to see if others have come across it and whether anyone has a way around it.
    This applies to Australian models which use the BCM to control the TUTD
    When using the 2007 YPRZ e38 and the matching T43
    OS ID AA
    BCC 9647
    OS 24239353
    Cal 24239647

    OK, so the problem is, when doing conversions, ie using these combos in say a Patrol or Early Holden or Hotrods or whatever, things seem to change.
    I have exactly the same model in my standard factory model 07/08 Statesman with no probs.
    But in a conversion, whether you have the BCM plugged in or not, the trans will hunt between 4th, 5th, and if you are lucky enough to get into 6th gear, no matter what you set the shift speeds and all the rest of it to, it makes no difference..... just randomly changes up and down gears....
    I have spoken to a couple of other tuning mates about it and they have had the same problem, and the only fix seems to be to change to a later tranny or the TCM out for a later model, and then use a matching ECM to suit and retune it.
    I either use the same model BCM and the VE shifter, or I have a special made Can bus TUTD controller that allows the use of any shifter, even column shifter, and it has TUTD buttons, along with a Video screen that shows things like gear position, RPM, Oil Pressure, Intake Temp, and Trans Temp.
    But these only control the TUTD and if not installed or unplugged, has no effect on transmission function.....
    In some cases with this early model, if you can get it into 6th, then switch to manual mode, it will hold it in 6th.... others wont.

    It seems, because of early protocol, and an early design TCM, that this cant be patched or updated, and the only fix is to replace with newer, which is a bummer for new customers that have just replaced their crappy old diesel or whatever, with a not exactly cheap conversion.... and now have to spend more if they were unfortunate to buy this early model......

    So before I write this model off, I thought I had better ask if anyone out there in propeller head land has found another way around this, taking into account we use quite a different BCM setup than USA, although in a conversion this shouldnt come into play too much without a BCM.

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    I don't know much about swaps, but do you have a good VSS signal...?

  3. #3
    Lifetime Member Chevy366's Avatar
    Join Date
    Oct 2006
    Posts
    1,603

    Default

    Aren't there shift kits that would allow manual shifting. My 4L80E kit came with way to convert to manual shift very easily.
    2005 1500 HD , Custom OS3 SD tune .
    2006 Trailblazer
    Dinosaurs and Plants gave their lives so that we may drive , long live fossil fuel .

  4. #4
    Member
    Join Date
    Sep 2010
    Posts
    74

    Default

    Quote Originally Posted by joecar View Post
    I don't know much about swaps, but do you have a good VSS signal...?
    Yes, Speed signal is fine Joe
    Actually in our VE model here in Oz, we dont use the VSS out signal, as the speed signal comes from the ABS to the BCM
    Holden changed this on the last and sadly recent discontinued model VF Commodore, and added the VSS circuit to Pin 16 on the TCM to the ECM,
    I add this wire to all my 6L80e harnesses in conversions, along with a signal out from the ECM, otherwise there is no signal out to run a speedometer.
    The TCM has an inbuilt speed sensor and uses this native data for its shift speeds.

  5. #5
    Member
    Join Date
    Sep 2010
    Posts
    74

    Default

    No the 6L80e has completely different functions to the earlier transmissions..... a long story...

  6. #6
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Quote Originally Posted by Hooter View Post
    ...
    The TCM has an inbuilt speed sensor and uses this native data for its shift speeds.
    Ah, I see.

  7. #7
    Lifetime Member Tre-Cool's Avatar
    Join Date
    Feb 2006
    Posts
    937

    Default

    Quote Originally Posted by Hooter View Post
    Yes, Speed signal is fine Joe
    Actually in our VE model here in Oz, we dont use the VSS out signal, as the speed signal comes from the ABS to the BCM
    Holden changed this on the last and sadly recent discontinued model VF Commodore, and added the VSS circuit to Pin 16 on the TCM to the ECM,
    I add this wire to all my 6L80e harnesses in conversions, along with a signal out from the ECM, otherwise there is no signal out to run a speedometer.
    The TCM has an inbuilt speed sensor and uses this native data for its shift speeds.
    Interesting, i'll have to look at my wiring as I put a 2010 model combo tcm/ecu in my vy ute & grab the speed from the ecu just fine.

    Back to the original problem, I have experienced this issue in a conversion someone did but as it was originally tuned with hpt & i wasn't getting paid to fix it. I told them to take it back to the original tuner to get it it all reflashed when it was known to work.

    Apparently sometime between the original tuner & me they took it to someone else & they messed with the tune & broke\corrupted something. Once the original tuner flashed it, it was good again.

Similar Threads

  1. Revision, 6l80e will not rev past 5k in gear, no up-shift at wot.
    By undergroundak in forum 6 speed/8 speed RWD/FWD Transmission Tuning (incl T43, T76, T87)
    Replies: 4
    Last Post: February 19th, 2024, 05:32 AM
  2. Replies: 0
    Last Post: December 5th, 2016, 12:09 PM
  3. swapping Camaro 6l80e to Vette 6l80e
    By secrt007agt in forum General
    Replies: 0
    Last Post: January 31st, 2016, 03:43 AM
  4. No Shift time adjustment in new 6L80E OS? Adjusting shift times in Torque Model
    By Protec in forum 6 speed/8 speed RWD/FWD Transmission Tuning (incl T43, T76, T87)
    Replies: 2
    Last Post: February 13th, 2013, 09:34 AM
  5. Conversions
    By Chevy366 in forum Lounge
    Replies: 20
    Last Post: July 28th, 2007, 04:43 AM

Posting Permissions

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