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Thread: E38 (12597121) tuning 2010 GM engine with No OBDII port connection

  1. #1
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    E38 (12597121) tuning 2010 GM engine with No OBDII port connection

    Okay,
    Strange one and need some assistance. Have a 1957 Chevy that showed up (total Show Car!) the engine was installed with a Street and Performance Harness and ECM. The ECM is a 12597121 E38. I hooked to the ODBII port on the harness and nothing. Traced wires and it goes to a third connector that does not even go to the ECM? Has anyone ever experienced this? is there places on this ecm to hook the serial wire for the ODBII port so we can talk and tune this ECM. I can post pics if that helps.

  2. #2
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    Simple. Run the wires from the ALDL to the PCM connector. There isn't just a serial wire. You need CAN+ and CAN-. The ALDL will need unswitched +12V and the grounds. And if Street and Performance did the ECM, don't be surprised if it's locked.
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  3. #3
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    So pins 28 to 6 and 27 to 14. Thanks.
    I assume this will then work with normal OBDII readers too. I want to make sure the owner can scan for issues down the road. (yes I will turn some off)

    Next too the issue of a locked ECM. Anyway to get the program that is in it out? Always have done factory set-ups so never ran into this before.
    We always take out factory ECM's or use a GM performance computer and they work fine (not locked)

  4. #4
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    Any Help?

  5. #5
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    Quote Originally Posted by Paul Powell View Post
    Any Help?
    With what? If you can't figure out adding a few wires to a harness then you probably shouldn't be working for hire.

  6. #6
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    Not about the wiring. About locked ECM. Never ran across one before. Do you just have to start over? have it flashed by a dealership? Can I flash it?
    Since I have never seen one I didn't know what is involved.

  7. #7
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    Street and Performance used LS2Edit on the ECMs they flashed and it was auto-locking everything. Everyone I've ever run into that was flashed by them was what is called Tuner Locked. Can only be read or flashed by the product/cable that locked it. Can't even be flashed or returned to stock by dealer level equipment. It changes the seed/key. At one time Geoff at EPS in Baton Rouge offered an unlocking service for a fee that changes the seed/key back to the proper one and preserved the tune that was in the ECM. It's been a few years since I've sent a locked ECM to him so I don't know if he even still offers that service. There may be others that offer that service but EPS is the only one I've ever used. The alternative is starting with a new ECM. Only way to know if it is locked is to try and read it.

  8. #8
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    And scanners still work on locked ECMs. You just can't read and flash them.