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Thread: Problem after pcm 97-02 swap

  1. #1
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    Problem after pcm 97-02 swap

    Hi all. I have a 97 Corvette automatic. I encountered a problem after swap pcm 97-02. I swapped the wires following the diagrams. The car works well, except for the trans. In position D, the car starts from third gear and then shifts into 4th without locking the torque converter. If you move the slate to position 2, you can engage second gear, 1 does not engage at all. From the settings in tune I don?t understand some of the wheel size calibration values, is it possible that this could have some effect? Here are some photos from diagnostic devices and my tune. initially in pcm there was a tune for the trans manual. Could it be that manual 411 pcm cannot be made to work with an automatic?

  2. #2
    Tuner Alex14SS's Avatar
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    When you swap a PCM meant for a manual transmission into a setup with an automatic, like in your ‘97 Corvette, you’re bound to run into some quirks. This is because the PCM controls not just the engine, but also how the transmission behaves. The issues you’re seeing, like starting in third gear or not locking the torque converter, are typical symptoms of a mismatch between the PCM programming and the transmission’s expectations. The wheel size calibration values you mentioned might influence the vehicle’s speed sensor readings, which in turn could affect shift points. Since the PCM was initially set up for a manual and now it’s being asked to manage an automatic transmission, it’s not surprising you’re seeing these issues. Your best bet is to get a professional tuner who can adjust the PCM settings to work correctly with your automatic transmission. They can correct shift points, torque converter lockup timings, and ensure your wheel size calibration is spot on for accurate speed readings. It might also be worth double-checking all the wiring and connections you’ve worked on to rule out any simple mistakes there. If you’re feeling up to the challenge and want to try tackling the PCM adjustments yourself, Blue Cat’s Trans Tool could be a valuable resource. It’s designed to help with precisely these types of transmission swaps by allowing you to modify transmission parameters in the PCM. This tool might help you bridge the gap between the manual setup your PCM was originally configured for and the automatic transmission you’re now using.

  3. #3
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    I understand this, but I downloaded the 2002 Corvette smautomatic transmission tune file from the repository and entered all the data that concerns the trans into my file. that is, the tune completely replicates the factory one for an automatic transmission

  4. #4
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    If you just copied differences into your existing file, you are just seeing a small portion of the tables that the ECM uses.

  5. #5
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    You would want to WRITE ENTIRE with a 02 Auto file. You can't convert a manual file into a AUTO. It is OK to force write these if you do a write entire.
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  6. #6
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    that is, I can?t just change the manual menu to 4l60 in my tune and add the values ​​to all the tables? Should I find a file from a car with the same operating system number and write it down completely?

  7. #7
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    Quote Originally Posted by Realcustoms View Post
    that is, I can?t just change the manual menu to 4l60 in my tune and add the values ​​to all the tables? Should I find a file from a car with the same operating system number and write it down completely?
    that is correct

    since this is a swap you don't have to worry about OS numbers. The 2002 C5 OS's are pretty stable. not a lot of choices.
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  8. #8
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    I apologize in advance for maybe stupid questions, but I?m new to this software, all my cars used to have only aftermarket pcm. So should I download the stock file for the automatic corvette from the repository and just write it to my pcm?

  9. #9
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    That is how I would do this yes.

    It's likely going to cost you credits to do so.
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  10. #10
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    I tried to write it down, but it writes an error because the operating system number does not match. but there is no such thing in the repository. Is it possible to somehow change the operating system number?

  11. #11
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    Write Entire, not Write Calibration.

  12. #12
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    happened! thank you all for your help