Results 1 to 2 of 2

Thread: Gear swap and speed/abs issues with EFI locked ecu

  1. #1
    Member
    Join Date
    May 2017
    Posts
    66

    Default Gear swap and speed/abs issues with EFI locked ecu

    LMM truck with 5 position switch.Before we did a gear swap I called the shop that tuned this truck 7 years ago and he said to buy a flash tuner for speedo calibration. We tried Superchips, Hypertech, HPT will not load ECM says locked. My EFI live will access trans side but adjusting anything there does nothing to correct speedo or output MPH. We installed 4,56 gears and customer had 35" tires installed. Has Speed miss match from from to rear. Nothing I change in speedo under trans section does anything except output 40 tooth, if I change that it will then set 1st ratio codes. Any Ideas to unlock or fix speedo/abs codes miss match.

  2. #2
    Member
    Join Date
    Oct 2010
    Posts
    81

    Default

    Must be changed in the ECM. I've played with it extensively on that platform, using multiple TCM combos from other GM vehicles. Seems it reads the pulse wheel on output shaft and does not care what the TCM speedo calibration say.

    Sent from my SM-G892A using Tapatalk

Similar Threads

  1. 05 Vett E-40 ECU P0601 ROM Error - New ECU Swap Question
    By brossjd in forum Gen IV V8 Specific
    Replies: 4
    Last Post: August 20th, 2017, 04:48 AM
  2. 2005 c6 vette how to change gear ratios in file after gear swap
    By AllOutPerformance in forum 6 speed/8 speed RWD/FWD Transmission Tuning (incl T43, T76, T87)
    Replies: 2
    Last Post: September 21st, 2016, 08:48 AM
  3. Replies: 3
    Last Post: November 14th, 2012, 05:31 AM
  4. locked ecu
    By dags in forum Gen III V8 Specific
    Replies: 6
    Last Post: August 13th, 2012, 02:29 PM
  5. Gear Swap and now service brake system/abs light
    By exploder in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 0
    Last Post: May 19th, 2009, 08:04 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
  •