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Thread: 2002 Jeep Grand Cherokee help.

  1. #1
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    2002 Jeep Grand Cherokee help.

    Im currently tuning my brothers 2002 jeep grand cherokee 4.7 5-45RFE. The only issue im currently having is that no matter what I do I cant get the transmission to shift when I command it to. i've raised shift points to from 5,800 to 6,000 rpm and nothing changed. So I changed it to 6,600 rpm and it seems to shift at a lower RPM. I've obviously changed the other parameters with it that could effect it but still nothing. Does anyone know what I could do or if there's something hidden? Thanks!

  2. #2
    Tuner in Training
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    The 99-04 WJ with the 4.7, has a separate controller for the transmission (TCM). Are you able to access that? What all can you access, as far as shift points and such, on the jtec? I have a 04 4.7 WJ myself, just a offroad toy on 35's, so I've never even thought to have tried plugging hpt into it. I'd do it now, but I have about 35% of the wiring out of it currently.

  3. #3
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    I have an 04 WJ. You can not change shift points natively via VCM Editor on Release or Beta. I've tried and "trick" and does not change.
    If you need a higher WOT Shift point, edit the fuel cut limit and manually shift it.

    However, I've fine tuned the Torque Converter lock and unlock to make it drive like a 2010 RAM with a 545RFE, Rapid engage and disengage right where I need it to.
    My tranny is modified so results may vary.

  4. #4
    Tuner in Training SRTRhino's Avatar
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    Did you raise or lower the delta throttle table to lock to convertor in 3rd and 4th?

    Quote Originally Posted by SonoranTech View Post
    I have an 04 WJ. You can not change shift points natively via VCM Editor on Release or Beta. I've tried and "trick" and does not change.
    If you need a higher WOT Shift point, edit the fuel cut limit and manually shift it.

    However, I've fine tuned the Torque Converter lock and unlock to make it drive like a 2010 RAM with a 545RFE, Rapid engage and disengage right where I need it to.
    My tranny is modified so results may vary.

  5. #5
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    can i use mpv13 to tune a 2002 4.0 jeep grand cherokee. i dont want to brick the ecm