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Thread: E38 ECM auto to manual trans solution?

  1. #1
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    E38 ECM auto to manual trans solution?

    So after searching endlessly for a reasonable solution to try to make a e38 with an auto trans OS work with a manual trans swap I can?t find anything definitive short of buy a MDI 2 (or clone) or snag a vin#
    To buy one programmed by vin- and an endless array of other piecemeal solutions. I?ve been to the Dealership to have them replace the automatic os in the e38 I have to a corvette os suggested here somewhere.... no go -I was told FM no longer does such. Search junk yards still can?t find. Any other ideas?!? Any help would be greatly appreciated!!


    Stroked ly6 (408)
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  2. #2
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    The most straight forward option is an E38 ECM programmed as a 2009 Corvette LS3 manual transmission. This would require that you also change the Throttle Body and Accelerator Pedal (APP) to match (i.e. 2009 Corvette items).

    Where are you located ?

  3. #3
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    I’m located near Houston Tx..... yes I read that I could use the 09 vette tune but it requires a change from OS 12630502 which is what I have in my ecm to OS 12628990 which is the vette at least that’s what I read on the board.

  4. #4
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    E38 ECM OS 12630501 that you have is common to 2009 Trucks. Corvettes of that same year generally used E38 ECM OS 12628990.

    Yes - you would need an E38 programmed as a 2009 Corvette, and you would also need to change your Throttle Body and APP to Corvette pieces.

    You are in Texas - there is a company that can make a Truck based E38 ECM OS work with a manual transmission, but they don't ship to the USA.

  5. #5
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    Quote Originally Posted by Jon S. View Post
    Yes - you would need an E38 programmed as a 2009 Corvette, and you would also need to change your Throttle Body and APP to Corvette pieces.
    I'm aiming to do something similar. I'll be starting with a 2014 Camaro ecm, and intend to drive a 2010 5.3 engine. I was told by a very skilled tuner, that the throttle bodies are easily interchangeable in the tune. The throttle pedal isn't, but that's a non issue for me. Am I hoping for too much, that this Camaro ecm will be able to be tuned for a Vortec intake and throttle body?

    Edit to add to the question. I've been reading a number of responses on this topic recently, including some by you. I see mention of Camaro operating systems being less than ideal, and that Corvette is highly recommended instead. Does this only apply for 2010 model year e38's? Or does it apply to all 2010 and up e38's?

    My brother is a GM tech at a dealer. He said he'll readily reflash a ecm for me, if I give him the VIN I want him to use. I've got a 2010 e38 from a truck. Should I have him flash a Corvette ls3 tune, or a Camaro ls3 tune to my ECM? I have the VIN and BCM from a 2014 ls3-equipped Camaro. I was intending to have him flash the ECM to match, but now I'm having second thoughts.

    In order of what's most important
    Manual transmission
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    Last edited by kipps; 09-22-2020 at 10:46 PM.

  6. #6
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    Ya it’s a sticky one- I’m kinda married to the manual trans so I ordered a Holly Terminator x I will continue to look for a junk yard e38 from a corvette cause I have the harness all done.... I can always find something to do with the extra-THANKS!

  7. #7
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    Quote Originally Posted by kipps View Post
    ... I was told by a very skilled tuner, that the throttle bodies are easily interchangeable in the tune ...

    Your "very skilled tuner" must have a difficult time getting liability insurance coverage - as sooner or later something unexpected will happen using that approach. These unexpected events are most often a "dead" pedal from time to time - but then there was that massive recall by Toyota a number of years ago for a "runaway" throttle condition.

    The best (and safest) method is to make certain all of the Electronic Throttle Control components match - ECM program, Throttle Body, and APP.

    Do it right, do it once.

  8. #8
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    Quote Originally Posted by Jon S. View Post
    Your "very skilled tuner" must have a difficult time getting liability insurance coverage - as sooner or later something unexpected will happen using that approach. These unexpected events are most often a "dead" pedal from time to time - but then there was that massive recall by Toyota a number of years ago for a "runaway" throttle condition.

    The best (and safest) method is to make certain all of the Electronic Throttle Control components match - ECM program, Throttle Body, and APP.

    Do it right, do it once.
    #1, the APP is routinely swapped on these builds. The Corvette pedal fits the classic pickups a lot better than the stock Silverado pedals do, so folks routinely switch them. The APP is nothing but two voltage divider circuits. If the resistance on each voltage divider is close enough, it will work fine. See the attached pic.

    #2, I'm using the truck intake instead of the car intake, for the higher bottom-end torque bump. Unless the throttle body's will interchange on the manifold, which I don't think they will, I'm forced to use the truck throttle body as well.
    Attached Images Attached Images

  9. #9
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    Quote Originally Posted by kipps View Post
    #1, the APP is routinely swapped on these builds. The Corvette pedal fits the classic pickups a lot better than the stock Silverado pedals do, so folks routinely switch them. The APP is nothing but two voltage divider circuits. If the resistance on each voltage divider is close enough, it will work fine. See the attached pic.

    #2, I'm using the truck intake instead of the car intake, for the higher bottom-end torque bump. Unless the throttle body's will interchange on the manifold, which I don't think they will, I'm forced to use the truck throttle body as well.

    I have been doing this full time for 20 years - have never had a problem - and have fixed quite a few problems from other suppliers and "tuners".

    Your APP photo is a fool's errand. The some APP outputs are SIMILAR but are never the SAME. It will sometimes take a few drive cycles for a problem to appear - or some "tuners" disable all of the safety features and DTCs - that is a law suit waiting to happen.

    You seem like the type that loves to argue - and knows everything - despite having not actually done much of anything.

    Best of luck to you - I will not being answering any of your future questions.