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Thread: mismatched ecm

  1. #1
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    mismatched ecm

    Hello, I purchased a 2017 6.2/8l90 combo and it turns out the E92 ecm that came with it is for a 2016 5.3/8l90 combo. The T87A tcm came attached to the trans and I think it's correct for the trans. Can I just dump a 2017 stock 6.2/8l90 tune from the repository onto the 2016 E92 and be good to go?

  2. #2
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    No. ECM and TCM must match

  3. #3
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    as an a e92A and T87A or both from the exact vehicle?

  4. #4
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    Both for the same exact vehicle and operating systems.

  5. #5
    Tuning Addict 5FDP's Avatar
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    You could find a E92A and then have it programmed with a GM tool to a VIN number that worked with both the PCM and TCM, then they'd be matched.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  6. #6
    Advanced Tuner IARLLC's Avatar
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    I prefer the 2016 (E92/T87) by far since tuning the PCM and TCM cost a lot less time and money ($100) and you can actually read the trans tone instead of a generic download every time. To run the 2016 electronics on a 2017 you will need a different high pressure fuel pressure sensor (4 contact) on the fuel rail and an additional wire for it. The T87 needs to come from a rig with the 8L90E of course. Since you will be able to adjust for gears and all it does not have to be an exact match...but it helps get going if it is the same combo that the setup originally came with.

    If you do decide to run the 2017 electronics, as 5FDP said, you can just buy the E92A and have it GM programmed to match the TCM combo. But as far as making it all happy in a swap you will end up paying $200 just to get to tune the PCM then either have your T87A unlocked ($200) and licensed ($200).

    or

    For the TCM you could go through the process of setting up a T87 to work with the combo. This would have to be done exactly as I have outlined on these forums. A number of people have tried it and failed because of a lack of GM tools and/or lack of similar vehicles to use for initial programming.

    For a swap I lean strongly toward the pre-2017 stuff.

  7. #7
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    I just oredered a E92/T87 combo tuned for a 2017. As I understand it a T87 will operate a 2017 8l90 just fine.

  8. #8
    Advanced Tuner IARLLC's Avatar
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    Quote Originally Posted by Sodak75 View Post
    As I understand it a T87 will operate a 2017 8l90 just fine.
    I have run T87 on 2017 Silverado rally trucks with no problems. The details are all available on this forum.

    As far as running an E92 on a 2017 motor, the PCM has to know how much fuel pressure is on the high side and the 2017 uses a different high pressure fuel pressure sensor with 3 contacts instead of 4. So I suppose that running the motor on an E92 would be as easy as replacing the sensor with one from a 2016 and adding the 4th wire.

  9. #9
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    Would the T87A necessarily have to be unlocked if this is a very stock configuration? This isn't a hot rod and I'm not looking for anything different than stock truck calibration just in my 75 GMC.

  10. #10
    Advanced Tuner IARLLC's Avatar
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    Even in a stock vehicle you get noticeable improvements from a custom calibration. In addition, will tire height, gear ratio, and weight be the same as the donor vehicle? If not, there will be even more room for improvement in shift timing and characteristics.

  11. #11
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    Ok gotcha, I was thinking the tire height and gear ratio changes where made on the ecm side but yeah that will all be different on the swap.

  12. #12
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    @sodak75 what ever came of this? I have a 2016 5.3 8L90 and just swapped with 8L90 from 2018 6.2. I?ve learned that my T87 TCM isn?t compatible so I?ve purchased a T87a. Now I?m worried that the new T87a will not be able to program to my e92 ECM.

    What came about yours? Any info helps