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Thread: Delayed shifts not matching shift speed

  1. 07-18-2014 #1
    Hoooper
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    Delayed shifts not matching shift speed

    Newly installed 5.3 in a jeep. 4l65e transmission using slightly modified stock 2005 Yukon tables. Under 25% throttle the transmission does not initiate the shift until around 25 mph. The shift tables show that it should be shifting at 12 mph under that condition and once it does shift it is very slow. I used vcm scanner to check the speed to make sure the computer was reading the correct speed and it did show the right speed. The same situation goes for all of the gears and various throttle application.

    In addition, it does not seem to downshift to first when coming to a slow, and it has tried to downshift into first past fuel cut. Seems like a tune issue, but I cannot figure out where my mistake is.
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  2. 07-18-2014 #2
    5FDP
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    In the trans tab it says it's running a 4L60e still, but you have a 4L65e. Would that matter enough to cause these issues??


    Also under your PE in the fuel table you really need to adjust that EQ ratio, the way you set it up is not safe. You have it going super lean in the power band. You want to be around 12.5ish or so, but to be on the safe side I like to run it slightly richer if you don't own a wideband. Also reduce the enable torque to 50-75% and set the RPM delay to zero and increase the ramp in rate to 2.0.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.
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  3. 07-18-2014 #3
    Hoooper
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    Transmission menu isn't giving me an option for 4l65e. Maybe I need to go grab a tune from the repository for a silverado ss which is what the transmission came from, and then modify it to work with the 5.3.

    Thanks for the suggestion on the pe changes. I wonder if this pcm was tuned at some point before I got it.

    Edit: just checked and the ss tunes had only 4l60 as the trans also. Program probably didn't change the name, I would expect the control is the same since its basically the same trans
    Last edited by Hoooper; 07-18-2014 at 10:36 PM.
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  4. 07-19-2014 #4
    Hoooper
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    Looking at my logs, the shifts match almost perfectly with the hot mode map. This doesn't make sense unless the stock sensor is busted or the computer gets somehow locked into hot mode until reset. I will try changing the hot mode map temporarily and see if there is a change
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