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Thread: Throttle Torque Source - VSS Limit

  1. #1
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    Throttle Torque Source - VSS Limit

    I need some help determining what is causing my Throttle Torque Source to change from "Pedal" to "VSS Limit" during Wide Open Throttle Runs

    If you look at 1:19.956 elapsed time you can see the Throttle torque source switch from Pedal to VSS Limit, you can also see the injector pulse width get cut

    then when you look at 1:21.086 and 1:23.345 you can see again the throttle torque source switches from Pedal to VSS Limit and the Throttle Position Sensor is showing the throttle position to be less than WOT (86%) even though the Accelerator Pedal position is maxed out at 91.4% when the throttle position sensor is showing less than (86%)

    I've looked all over the log, I have no idea what to look at next or what to change to eliminate this. It's very frustrating as the car will buck or slow down then accelerate when in the middle of a WOT run at the track.

    The ECU is for a 2012 Challenger R/T
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    Last edited by rich s; 11-04-2021 at 10:19 AM.

  2. #2
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    Also.... throttle light (lightning bolt) will flash when the anomaly occurs

  3. #3
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    Maybe a dumb question but how fast are you going when this happens

  4. #4
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    it has happened as slow as 103mph....

  5. #5
    Senior Tuner TheMechanic's Avatar
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  6. #6
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    the tables are the same in my original pull file. but I will look into it a little more

  7. #7
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    you could also try here Screenshot (9).png . Do any codes set after your runs for etc or vss?
    When in doubt, Throttle out

  8. #8
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    im having same issue, i will attach 2 files, 1 has the issue and the other does not, if you compare you will find the differences, i dont have time yet to double check but almost sure in my case is the INDICATED TORQUE PER CYLINDER TABLE..
    i made those changues because im fightning a soft 1-2 shift, i had to mess some with injector data to output higher TQ output calc, then i modified INDICATED TORQUE PER CYLINDER and it did worked to output higher TQ output calc. but started to close throttle and show VSS LIMIT, i will look into it more tomorrow..
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  9. #9
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    Quote Originally Posted by alf View Post
    you could also try here Screenshot (9).png . Do any codes set after your runs for etc or vss?
    no codes for VSS.

    the VSS spark is already set to disable. I'll zero out the table.