How does CTS' Adaptive Transmission Work?
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Cadillac CTS First Generation Forum - 2003 - 2007 Discussion, How does CTS' Adaptive Transmission Work? in Cadillac CTS Coupe, Sport Sedan and Sport Wagon Forums; I've done some searching on here and other forums and have yet to find concrete information... even the GM powertrain ...
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    AsAkAs's Avatar
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    Question How does CTS' Adaptive Transmission Work?

    I've done some searching on here and other forums and have yet to find concrete information... even the GM powertrain site lacks info... about our Adaptive Transmission. I know it adapts to driving styles, but does anyone know exactly how it adapts to our driving styles?

    What kind of driving causes changes, and i don't just mean "spirited or sporty" there has to be a way to break it down... lifting the throttle quickly, quicker acceleration, flooring it... does it respond to other inputs like cornering, or just throttle control? Does using shift mode more often teach it to drive harder in just sport mode, or in both modes??

    What does it do to adapt? Does it increase shift points, make the ETC more agressive, shift harder? How long for changes to take effect?

    Also, is there a way to reset it to factory defaults without going to a dealer or hooking it up to a Diagnostic Machine?

    How exactly does this miracle "smart" automatic transmission work, i'd like to know what makes it tick in that little electromechanical brain.

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    Franchise2005 is offline Cadillac Owners Fanatic
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    Re: How does CTS' Adaptive Transmission Work?

    Thats a good question yo i was wondering the same thing

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    Re: How does CTS' Adaptive Transmission Work?

    No one has any insight?

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    Re: How does CTS' Adaptive Transmission Work?

    I tried some searches like "Howstuffworks.com" but really didn't find anything.

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    Re: How does CTS' Adaptive Transmission Work?

    Obviously, it's not the transmission that adapts, but the computer software that controls it. I have no idea what inputs it uses, or it's algorithm for optimizing shifting, but I'm sure it's not as complicated as the ECU which optimizes fuel, timing, spark, etc., thousands of times each second.

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    Re: How does CTS' Adaptive Transmission Work?

    Quote Originally Posted by odysseus
    Obviously, it's not the transmission that adapts, but the computer software that controls it.
    Essentially they are one and the same as they work together to produce the results, i'm just curious what it does to discover your "Style" and how it accomodates that driving enthusiam, or lack thereof

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    snosrap is offline Cadillac Owners Member
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    Re: How does CTS' Adaptive Transmission Work?

    I purchased a 2006 CTS with all the bells and whistles on May 29th. I have had it at the dealer twice. The transmission appears to have a mind of its own. They say it is adaptive shifting. The dealer reset the TCM (Transmission Control Module). It ran great for a week. Now the SOS (same ole sh*t) It’s my wife’s car. I don’t want to hear her bitching that’s why I bought a 2006 Cadillac. Personally I am not impressed. Has anybody else had transmission shifting problems???

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    Re: How does CTS' Adaptive Transmission Work?

    Quote Originally Posted by snosrap
    I purchased a 2006 CTS with all the bells and whistles on May 29th. I have had it at the dealer twice. The transmission appears to have a mind of its own. They say it is adaptive shifting. The dealer reset the TCM (Transmission Control Module). It ran great for a week. Now the SOS (same ole sh*t) Itís my wifeís car. I donít want to hear her bitching thatís why I bought a 2006 Cadillac. Personally I am not impressed. Has anybody else had transmission shifting problems???
    Geez..I love my auto tranny. It's flawless. The Sport Mode is unreal. You must have a problem 'cause it's not typical.

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    Re: How does CTS' Adaptive Transmission Work?

    that sort of behaviour is not typical.
    what specifically is it doing?

    my auto is smooth as silk and nice and fun in sports mode.

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    Re: How does CTS' Adaptive Transmission Work?

    stealth dubbed is correct.
    hey dubbed.

    diconnect the battery for about 30 min then reconnect, it wil reset to factory defaults.

    as to how the smart transmission works. man this is a toughy to try to explain. okay for one, it is not the transmission that adapts really, its the software controlling it. the computer uses a lot of inputs, and algorithms to sort through data and adapt to driving styles. its kind of complex. one such thing is if you hit the gas then quickly hit the brakes the standard shifting (not sport) will start to use engine braking because its thinks that what you want. there are a lot of variable and I dont know them all. the computer controls shift points, both up and down, line pressure which affects the harshness of the shift and a ton of other components of the transmission.
    -K

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    Re: How does CTS' Adaptive Transmission Work?

    my o6 feels like it downshifts on its own,is that normal

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    Re: How does CTS' Adaptive Transmission Work?

    Quote Originally Posted by CADIMAC52
    my o6 feels like it downshifts on its own,is that normal
    Sure is normal but in the sport mode it's more noticeable.

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    Re: How does CTS' Adaptive Transmission Work?

    wow i had no idea our cars were equiped with such transmissions lol... but as for my experience so far, it drives smooth and perfect... when i floor it, it responds quickly when im cruising its unoticable... two thumbs up!

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    ewill3rd is offline Cadillac Technician
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    Re: How does CTS' Adaptive Transmission Work?

    The computer monitors engine rpm, and transmission input shaft speed.
    Sometimes cars use the rpm or crank sensor as an input, some use an additional sensor inside the transmission or even one that monitors the bumps on the torque converter to see how fast the input shaft is spinning.
    it also monitors the output shaft speed on the transmission, often this is the Vehicle Speed Sensor or VSS.
    Since the computer knows the ISS and the OSS it can calcluate the actual gear ratio that is engaged and monitor transmission internal components for slippage and even help you identify which parts might be failing. We use a "range reference chart" to see what components are "applied" and "holding" or "overrunning" to identify possible suspects.

    At any rate, the transmission has tables for shift points in the controller software. It monitors the time it takes to transition from one gear ratio to another and alters apply pressure (sometimes just line pressure) and shift solenoid timing to keep the shifts inside a certain time window and control slip speeds. As you drive it uses complex algorithms (programs) to anticipate what kind of shifting need done and alters the data in the table as required to maintain shift speed and feel.
    These tables are called "shift adapts".
    They can be reset with the Tech 2 (scan tool).
    Typically the only time you want to reset the adapts is if you do transmission work. The adapts will start to change as soon as you start to drive.

    Sometimes unhooking the battery will reset the adapts, sometimes you have to do what we call "clearing the caps". Meaning there are power storage capacitors in some systems in the car (SIR for example) that can maintain memory in the event of a power loss. You can clear the caps (or discharge the capacitors" by disconnecting the battery and holding the positive and negative cables together for a few seconds.
    Basically the capacitors just lose their energy because both ends are connected together.
    Some computers store the table data in non-volatile memory, like your radio.
    Newer computers have chips that hold their programming even though power is lost. Years ago that was only true for a hard programmed ROM chip. All RAM would reset with power loss.... long story.
    Anyway with EPROM and EEPROM technology it's not really so anymore. Carmakers can do lots of fancy things now.
    Point being, unhooking the battery may work on some cars but may not on others.

    I can get you more technical information from the manual if I have time and if you guys really want it but it might be harder to understand than my "simple" explanation.

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    Bfegan is offline Cadillac Owners Member
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    Re: How does CTS' Adaptive Transmission Work?

    Ewill,

    That's a great explanation. Thanks!

    Basically it sounds like we have the equivalent of a european tiptronic. When you have time, please post the more detailed stuff from the manual.

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