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Thread: ADAPTS procedure

  1. #31
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    Heya Guys,
    Sorry been out for some time, but since this is a sticky, I thought I would elaborate on my experience with the Fast Learn procedure and when it is best to use it...

    Since this option has been out for a while now, I'm sure most have at least tried the procedure and many have had different level of luck with it. So rather than totally go through the steps of the procedure, which have been stated in earlier posts, I'll just explain what is happening during this procedure and what the tranny is actually looking for...

    On a stock vehicle (engine tuned spot-on, transmission all stock), the procedure works quite well. Modified transmissions or cammed engines will experience varying results, more on the modified scenarios later...

    Do all resets for transmission, then hit trans preset before initiating the learn process. By hitting the trans preset, you are actually telling the transmission to start learning from the oncoming and off going clutch pressure settings as well as the clutch volumes you have in your tune. I know it is common practice by some to set the Volumes higher or lower to make the transmission shift correctly, when actually, in a perfect setting, this is the exact measurement in cc's it takes to fill the clutch. Ideally this will only adapt as clutches wear. So being very close in this area will make a HUGE difference in how quick you arrive at the perfect tune. Some of the things that may indicate you are off in the volumes would be an extremely hard shift executing at a much faster time than you have set for shift (in this case the volume is too high), or the trans will flare hard on initial shift, usually as an initial hit then release flare (may indicate the volume is too low). The TCM is only as smart as the programming, so if you have 50 cc's set for your 5-6 shift, and the clutch pack actually needs 60, the TCM stops at what it thinks to be 50 cc's. Therefore the pack is not filled and you get a big flare that it will compensate for eventually IF you are close enough. If you are too far off, it may never totally figure it out and it may even think the clutches are totally worn out.

    Once fast learn is initiated (Stock Vehicle), TRANSMISSION MUST BE ABOVE 150 degrees min and Clutch Purge must be enabled for this procedure. . The scanner will ask you to put the vehicle in D. Hold brake pedal for duration of the process or it will abort. The first thing the transmission wil do is purge the clutches so no air is present. once that is completed, it will sytematically apply the volume and pressure to each clutch pack. After the pressure is applied, the TCM will slowly ramp down pressure until it sees a release of the clutch pack allowing it to spin again. If you listen very carefully you can hear it in the transmission when it happens. It will do this for each gear so it can memorize the pressures for each shift, to engage and disengage each gear. Only in a very few instances did the TCM ask me to select Reverse. So if it does not ask you, don't feel it didn't do what it was supposed to. Once the TCM is done, it will show "completed" and the vehicle will drop to a low idle.

    Cammed vehicles and tuned engines may experience the vehicle dying when the procedure is completed. This is normal. This is due to the air signal dropping to low for the ECM to catch the throttle drop. Keep in mind, the idle setting after Fast learn completes is approx 500 RPM. If you can't idle you cammed engine this low in the first place, it will surely die when the fast learn completes. It is a default idle rpm set by the system after this procedure is completed. Normal. Shut the ignition off and wait 3-5 minutes before attempting to restart so the ECM and TCM reset or will will still not have forward or reverse gears. If you restart and it doesn't go into drive, you did not wait long enough.

    Modified transmissions cause another set of anomalies. Modified clutch packs, alto red materials, or clearence issues will not play well with Fast-Learn. So, let's say you just got done with a modified transmission re-learn and took the vehicle out on it's maiden test drive. Shift flares? Bang Shifts? Slipping clutches? Anything sound familiar? it sure did to me! lol. Ok so what went wrong? The first thing I thought was "My tune is waaaaay off!". This may not be the case and I learned that the hard way. Maybe this info will save some heartache for others....
    I was doing a fast learn on a modified transmission and finally figured it out. The TCM applies pressure to each clutch pack and slowly releases pressure until slip is achieved. This is how the TCM learns what the lowest pressure is needed to keep the clutch "engaged". BUT, with Alto Reds, or other materials for that matter, or even added clutch plates, the friction coeff is much higher. The TCM will have to drop to a lower pressure than what is really needed in real world operation and "ADAPTS" itself to that setting. So when you drive the vehicle, the TCM "thinks" it knows what it should be applying the oncoming and offgoing pressures at, but transmission slips, flares, bang shifts, etc. IF your tune was indeed correct in the first place, it may figure it out and then clear up some if not all the way. It is VERY easy for this scenario to cause you to "chase your tail" by making you constantly change you tune in an attempt to fix the tranny shifts.

    The same thing is true for stall converters. Even in a stock transmission. The idle speed that is raised during a relearn may not be enough to apply the correct torque to the clutch packs. The TCM is looking for the exact pressure that slip is achieved but cannot see it happening. The TCM then thinks that lower pressure is needed to hold the clutches engaged and again, you feel slips, shift bangs, and generally sloppy shift times. This is all true IF THE RELEARN PROCESS ACTUALLY COMPLETES WITH A STALL CONVERTER! Many will find that the process will consistently fail and this is due to the fact that TCM did not see proper slip happening when it thought it was going to and thinks there is a problem. It aborts and says "failed".

    So what the moral of the story? Well, if you have a stock transmission, the fast learn procedure is a godsend. If your tune is correct, you will be amazed at how well the transmission works the first drive out of the garage. If you change things in your tune for a stock transmission, especially clutch volumes (which you shouldn't ever have to do on stock) or oncoming/offgoing pressures, ALWAYS DO A RESET THEN FAST LEARN. It is not so much needed if you change your shift timings slightly, that will adjust as you drive a few miles of stop and go. If shift timing is all you change, a relearn is not necessary.
    If you have a modified transmission, or a stall converter, your experience may not always be a good one. Welcome to the world of performance tuning lol! You are now required to program that tune correctly yourself. I would say to try a fast learn once to see how it turns out on your particular setup, because it "may" work fine. But if you have any mod work done to your tranny or stall, and it does fail the process, it is normal. There is not something necessarily wrong with the tranny, it just means that the TCM doesn't recognize what you have done since it is looking for "stock" results.

    The trans reset and preset features are still very handy. If you are one that had the fast learn fail, and you are changing things in your tune, it is still very helpful to use the reset feature and then hit the trans preset but then don't do a fast learn. What you are acomplishishing by doing this is you are forcing the transmission to use YOUR exact tune setting to operate the transmission. If you were lucky enough to hit everything spot on in the tune, it will work correctly immediately. You will see just how good your tune is the first time it goes through the gears. If it felt good the first time through the gears, that means you tuned it well and it will stay pretty close as long as your timings are set correctly for the shift pressures you programmed. Keep in mind that if you set agressive shift pressures that would require a short shift time, but you have a longer shift time in your tune, the TCM will start changing the pressures to adapt to your tune's specified timings. This is why some experience a nice firm shift on initial drive but then the shifts get softer and sloppier. This is why some disable adapts to keep that initial feel but that is really just masking a problem in the tune and it could be a minor one at that. If it shift flares, bangs, or slips immediately through the first set of shifts, you are off in the tune. Adapts will start taking effect after the first shift of each gear so the TCM will try to correct what you have wrong. If you are close enough, it will figure it out. Otherwise, tune changes will be required. One thing I have tried with pretty good sucess is to turn of adapts for the tuning procedure, this will keep the TCM from performing corrective changes to your tune. This can be a bad thing if you are far off from the perfect tune!! BE CAREFUL! Damage can and will happen if problems are ignored. Adapts can be your best friend! This TCM is smart enough to help your fine tune your transmission but it's like having too many "cooks in the kitchen" so to speak. You may be trying to change the same things that the TCM is trying to correct. Welcome to the insanity loop! That is the main reason I feel this transmission is so frustrating to most when they attempt to refine it.

    Bottom line is the relearn is there solely to learn the oncoming and offgoing pressures. It will then adapt from there to reach your tune specified upshift timing goals, shift intertias, and pressures need to make that all happen as you drive.

    I hope this helps explain a little of whats going on and why your experiences are so varied from one tranny to another.

  2. #32
    Lifetime Member Boost's Avatar
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    Thank you for the info Longslyde!
    '12 Caprice PPV 6.0 L77 - daily transportation
    8.7 @ 84 (1/8 mile) bolt-ons

    '02 Silverado RCSB 5.3 L59 - regularly street driven
    8.2 @ 86 (1/8 mile) stock cam and spray
    8.6 @ 84 (1/8 mile) cam and heads no spray

    Our YOUTUBE CHANNEL featuring the Silverado

  3. #33
    Senior Member Dieselman's Avatar
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    Big thanks from me too. Excellent work !!

  4. #34
    Junior Member T2000's Avatar
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    Great info - thanks for sharing

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