5 speed transmission swap

Comments

• Mr_Shiftright Member Posts: 64,481

  January 2016

  We've been talking about your question in our Answer Department. as well.

  0
• thecardoc3 Member Posts: 5,747

  January 2016

  You can't just swap the transmissions. The PCM will be looking for the automatic transmission solenoid circuits and the input and output speed sensors (among other things) and will be coding and blocking other tests from running. Even then if you tried to re-flash or substitute a PCM to account for that you need to know what challenges you are going to have to overcome.
  
  To convert this to a manual, you will have to get GM to assign VCI software for that VIN as a manual transmission on GM's TIS site. The only other way would be for someone to re-write and flash the software outside of GM's control and that's not advisable for street use.

  0
• Mr_Shiftright Member Posts: 64,481

  January 2016

  Why can't he use the donor vehicles PCM and harness?

  0
• thecardoc3 Member Posts: 5,747

  January 2016

  He "can" use them BUT... To do the job correctly at the very least the VIN that is programmed into the PCM needs to match the vehicle. There are a lot of today that a VIN mismatch really is a big deal. A VIN mismatch could easily cause an issue with emissions testing, especially in Ca. On Passkey III and newer systems the only way to retrain the theft deterrent is with GM's TIS and it will poll the VIN for that. It's also likely that the radio could turn off if the VIN stored in it and the PCM, and the BCM don't match.
  
  I could go on and on about this, but he would be way ahead to keep the truck as built and if required have the transmission repaired if that's what started the line of questioning.

  0