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Thread: JEEP JK HELLCAT 2500 RPM LIMIT IN park/neutral and drive too.

  1. #1
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    JEEP JK HELLCAT 2500 RPM LIMIT IN park/neutral and drive too.

    What would cause this RPM LIMIT and how do i fix that issue? Throttle torque source PID says: RPM LIMIT

    It happens at 2500RPM in Park/neutral or Drive..

    Log attached.

    Thanks in advance.
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  2. #2
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    Tune
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  3. #3
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    suggestios on how to fix this? been reading but cant find nothing,

  4. #4
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    Are you getting a DTC? Could it be Limp offset is too low?
    limit.JPG

  5. #5
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    I have tried different tunes and changues and have no succes, any pointer would be great, already tried what Homer suggested and noluck either.
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    Last edited by castorjames; 04-14-2019 at 03:08 PM.

  6. #6
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    Look in the trans section for rpm & gear limiters. I think some software development tossed that in the tcm area... might need to add in credits for that too...
    I have a burrito in my colon, yet refried beans come out...
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  7. #7
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    Quote Originally Posted by * _ * View Post
    Look in the trans section for rpm & gear limiters. I think some software development tossed that in the tcm area... might need to add in credits for that too...
    ECT/EOT RPM Limit are at 7000 RPM

    thank you
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  8. #8
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    Any help? I cant fix this issue, already look deep in the tune and cant find anything that will make it limit at 2000RPM, throttle torque source: RPM LIMIT
    attached the last test tune
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  9. #9
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    I am wondering if has to do RPM Limit TqRed table. Yours has a 100% reduction on the first two cells. You can try this, rescale the RPMs to -250 -200 -175 -150 -125 with values 25 20 18 5 0.

  10. #10
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    I have done quite a few Hemi swapped JK's but never saw one done using the 3.6 computer and a 3.6 calibration.
    Has this been done successfully before by someone?
    I am curious since I have been buying and re-VIN'ing V8 PCM's for shops that are doing these swaps into the JK's and would love to save them some money if it can be done.
    I know it's not much help for you in your situation other than letting you know that it can be done with a Hemi PCM and harness.
    I selfishly want to know if someone has made this work - at least you have it running..
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  11. #11
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    Quote Originally Posted by [email protected] View Post
    I have done quite a few Hemi swapped JK's but never saw one done using the 3.6 computer and a 3.6 calibration.
    Has this been done successfully before by someone?
    I am curious since I have been buying and re-VIN'ing V8 PCM's for shops that are doing these swaps into the JK's and would love to save them some money if it can be done.
    I know it's not much help for you in your situation other than letting you know that it can be done with a Hemi PCM and harness.
    I selfishly want to know if someone has made this work - at least you have it running..
    Thank you for taking the time.. The pcm is a 6.4L PCM,( it is not a 3.6L pcm) i sent it to B&G to update the VIN number and for the traction control to work etc..
    When we first build this car was the same process; I sent a stock 6.4L cherokee pcm, they updated VIN number and they provided a base tune, Car started and all was ok, we worked the tune and all was OK.
    Owner took car to the car wash, car didnt accelerated after that, owner thought water got into pcm, owner tried to open the pcm, fu$%3d the pcm...
    I started same process, sent a stock 6.4L to B&G, they updated vin number, base calibration, etc.. installed pcm on car, and im not been able to figure out this RPM LIMIT, so we cant finish this car... i dont really know where to look at this point, maybe try with a completely stock 6.4l pcm and when tune done send it to update vin number to match JK vin?

  12. #12
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    Quote Originally Posted by richhurley View Post
    I am wondering if has to do RPM Limit TqRed table. Yours has a 100% reduction on the first two cells. You can try this, rescale the RPMs to -250 -200 -175 -150 -125 with values 25 20 18 5 0.
    You mean ECM 44488-TORQUE REDUCTION on Misc Cutoff?? I missed that one,, i will try tomorrow and really hope this can be the solution.. i let you know and thank you.

  13. #13
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    Yes, that's the table.
    Last edited by richhurley; 05-20-2019 at 07:32 AM.

  14. #14
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    Quote Originally Posted by [email protected] View Post
    I have done quite a few Hemi swapped JK's but never saw one done using the 3.6 computer and a 3.6 calibration.
    Has this been done successfully before by someone?
    I am curious since I have been buying and re-VIN'ing V8 PCM's for shops that are doing these swaps into the JK's and would love to save them some money if it can be done.
    I know it's not much help for you in your situation other than letting you know that it can be done with a Hemi PCM and harness.
    I selfishly want to know if someone has made this work - at least you have it running..
    I'm in the middle of tuning a Hemi JK swap and it's running on the 3.8 PCM/VCM, having issues making the IPW do what I want. Tuning with the ANN on because of the altitude the owner claims he will be using it at occasionally.

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    THe ANN training values in a V6 PCM for a hemi?!?!? Why would you assume a V6 tune would run a Hemi?

    the VE tables are perfectly fine with altitude... thats the whole point of the BARO/etc.... ANN does *nothing* to help with altitude... Its really there to allow for stable operation with the VCT. (its a fancy way to do multi-dimensional VE tables)
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  16. #16
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    Quote Originally Posted by lafrad View Post
    THe ANN training values in a V6 PCM for a hemi?!?!? Why would you assume a V6 tune would run a Hemi?

    the VE tables are perfectly fine with altitude... thats the whole point of the BARO/etc.... ANN does *nothing* to help with altitude... Its really there to allow for stable operation with the VCT. (its a fancy way to do multi-dimensional VE tables)
    The company that sells the JK Hemi swap does some kind of proprietary modification to the V6 PCM to make it run the 5.7, they make a very nice plug and play kit and have been mass producing them for years. I called them about the hybrid PCM/OS asking questions and they seemed irritated at me for asking & said they don't recommend modifying the calibration so I disabled the ANN and had it dialed in perfectly in an hour and a half.
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    So i removed engine harness to inspect it as i couldnt fix the rpm limiter in the tune, someone told me about cam / crank SYNC with scanner tool, not sure if HP supports that function, anyways when i removed the cam sensor connector, the pin #1--5v had corrosion.. this 5v is shared with map, crank, and others.. so i hope this will be my problem, maybecar goes to reduced power cause that??