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Thread: Throttle not fully opening according to VCM Scanner Logs 2015 Durango 5.7

  1. #1
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    Throttle not fully opening according to VCM Scanner Logs 2015 Durango 5.7

    Hi guys. I've been reading and learning a lot here, so I can tune my 2015 Durango R/T with 5.7 hemi.
    I've done some tuning to boost my fuel economy on the highway with great results, gaining almost 5mpg on a recent trip to Washington for Memorial Day but looking over the logs, I noticed that my throttle is not fully opening.
    The logs show that my pedal voltage is about 4.63V at the highest and that equates to 92.5%, the throttle position get only to 85.9% and relative and commanded throttle is even less at 76.1%
    I've looked at special functions and did the electronic throttle re-learn. I've looked everywhere but can't find a setting where I can change the settings for throttle opening.
    Any guidance will be much appreciated.
    P.S. I'm using the latest beta suite.
    Throttle issue.jpg

    TIA
    Alex...

  2. #2
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    Quote Originally Posted by alexp View Post
    Hi guys. I've been reading and learning a lot here, so I can tune my 2015 Durango R/T with 5.7 hemi.
    I've done some tuning to boost my fuel economy on the highway with great results, gaining almost 5mpg on a recent trip to Washington for Memorial Day but looking over the logs, I noticed that my throttle is not fully opening.
    The logs show that my pedal voltage is about 4.63V at the highest and that equates to 92.5%, the throttle position get only to 85.9% and relative and commanded throttle is even less at 76.1%
    I've looked at special functions and did the electronic throttle re-learn. I've looked everywhere but can't find a setting where I can change the settings for throttle opening.
    Any guidance will be much appreciated.
    P.S. I'm using the latest beta suite.
    Throttle issue.jpg

    TIA
    Alex...
    Its an electronic throttle. For some reason 86% is what it shows at WOT

  3. #3
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    You mean, it could be a faulty TPS?
    Still, on most stand-alone systems there's a setting where you can set voltage to throttle opening relation, it's hard to believe this function is missing in HPTuners.
    Thanks,
    Alex...

  4. #4
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    Quote Originally Posted by alexp View Post
    You mean, it could be a faulty TPS?
    Still, on most stand-alone systems there's a setting where you can set voltage to throttle opening relation, it's hard to believe this function is missing in HPTuners.
    Thanks,
    Alex...
    These ECU's do not base anything off throttle percentage. All base everything off throttle voltages. Do that being said just make sure your all of your WOT voltages match and make sure that the trans throttle interpret matches your WOT voltage and don't worry about what percentage it shows because that is not what is really occurring

  5. #5
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    Hmm, interesting. Will definitely dig into it and check.
    Thanks!

    Alex..

  6. #6
    Right, Log TPS voltage and see what you get.

    A throttle not open fully isn't an issue AS LONG AS the manifold pressure equals the barometric pressure.....its actually preferred because it allows quicker response if the PCM needs to close it.

  7. #7
    Advanced Tuner f.creek-ranch's Avatar
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    Ford, Chevy, Dodge have all different throttle open percentages.
    this isn't an issue .

  8. #8
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    I'm still learning this thing and frankly, I'm getting a little confused. I've taken some logs on short and long drives. Can I put my logs in here and you guys, that know what you are looking at, can tell me if I'm reading them wrong maybe?
    TIA

  9. #9
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    The TPS voltage when the blade is physically fully open is around 3.84 V. The % for some reason is calculated using a 0 - 5 V scale, thus ~3.8 V will never read as "100%".

  10. #10
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    That explains it!
    But why? This is so dumb!
    Thank you!