Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!

Toyota/Lexus transaxle shift delay



  • hylynerhylyner Member Posts: 216
    I am NOT suggesting anyone immediately run down to the neighborhood automotive store to buy a performance enhancer, and yes, I am aware the device would probably void one's warranty. That's decidedly a no brainer.
    My ONLY reason for raising the point was to show how solutions are already out there. This is, after all, a "problems and solutions" forum.
    And yes, different makes/models of cars require different performance enhancing devices. That's why, when one buys one of these devices, it is necessary to specify which make/model one owns, so the appropriate device is purchased. They are make/model specific--look it up on the net.
    They come in all styles and shapes, with a variety of operating characteristics and user features. The simplest ones are straight replacement CPU chips, non adjustable nor programmable. Some factory chips are non removeable, so in these cases the performance enhancing device installs in line with the transmission CPU harness. For some units, what's changed stays that way until the new chip is replaced or the unit running in parallel is removed. High end units are dashboard mount, infinitely programmable, and are capable of providing a variety of different performance characteristics, even while in motion.
    No matter how one slices and dices this issue, it's not the deep, dark, unsolvable mystery that it's thought to be.
    That's all I'm trying to say.
  • wwestwwest Member Posts: 10,706
    My team, nor any reasonably competent software group, would EVER suggest simply reprogramming versus digging in and finding and correcting bugs in the current firmware.

    Were you to do so then your assumption would be that an aftermarket third party programming group is better than the factory and that's simply not going to happen.

    If you were doing it to improve torque/HP for track use then the new bugs you will surely encounter might be tolerable, otherwise.........
  • hylynerhylyner Member Posts: 216
    From the other forum--as promised--my response to yours:

    Look my friend, all I was trying to do was illustrate there's more than one way to skin this "elusive" hesitation cat. It isn't that elusive, and I believe you, more than most,should know that.
    These performance enhancement devices I've researched aren't for "track use" or "dragster application" or any other "competition" purposes. They're just another way to change one's transmission characteristics for a more user compatible attributes--assuming that's what the user desires. And they're cheap, easy to obtain, and there's lots of them around so the proof of their effectiveness is beyond question. Besides, any developer worth his or her salt knows the algorithms we're talking about in CPU transmission controls are about as simple as it gets. CPUs in these applications aren't quite the same as Lunar Landing Module controllers. I'm sure you have great programmers in your company, but they aren't any better or worse than a great many others out there. The application here is a relatively simple one, so it shouldn't be made to look more complex or difficult than it really is.

    Besides, those who claim they're really unhappy with their AV, or HL, or ES300, and who claim they'd rather deal it and eat the loss than drive it any longer, now have an inexpensive and perhaps viable alternative.
  • scoti1scoti1 Member Posts: 676
    The application here is a relatively simple one, so it shouldn't be made to look more complex or difficult than it really is.

    Maybe Toyota should hire you on then since they haven't quite got it figured out yet.

    Joking aside, I think wwest hit the nail on the head. Toyota likely knows what to do, and maybe it is a simple solution, but they just can't do it and still meet fuel efficiency and pollution requirements.

    So the question is, would use of these after market "fixes" compromise fuel efficiency? And if not, then maybe they aren't truly a fix for the problem.

    BTW, just cuz there are "lots of them around" certainly doesn't mean "their effectiveness is beyond question" as you stated.
  • wwestwwest Member Posts: 10,706
    "....isn't that elusive...."

    Initial complaints started in 2002.

    No fix as of yet......

    But you miss the real point. The part that seems to be the most elusive is the fact that a very few are experiencing the hesitation delay symptom. I have little doubt at this point that Toyota has already implemented all of the gas saving features described in the Sierra Research article within the firmware of all of the new 5-speed transaxles. But why has that resulted in a very few instances wherein this implementation results in a very noticeable, maybe even unsafe or hazardous circumstance?

    Therein lies the elusive firmware "BUG".

    My suggestion at this point is that Toyota should provide a transmission mode inverse to the "snow" mode. Basically a mode switch (shades of Edson DeCastro/Tracy Kidder) wherein the owner tells the transaxle to be aggressive with the shifting logic, "expect that I will floor the accelerator pedal at any, the very next, moment" and be prepared for same.
  • hylynerhylyner Member Posts: 216
    Guess I was wrong in attempting to offer constructive and creative solution options. It's clear collective emphasis here is polarized more or less on blame, in spite of forum titles to the contrary. I now have the distinct feeling there really isn't much interest in solutions after all.
    That said, I choose not to defend what I felt were helpful "food for thought" posts, nor will I take part in shooting them down with criticism when ideas like them appear.
    I explained very clearly why I posted what I thought might be helpful, so perhaps it's best to just leave it at that.
    If I come across any more constructive solutions, rest assured I'll do the same again.
  • wwestwwest Member Posts: 10,706
    No, constructive and creative ideas are really what this forum is all about, especially until a solution is found. Just remember that when any of us come up with an idea we must be willing to accept the critiques.

    Remember my idea of modifying the IAT? Or the one about it being the inappropriate use of a solenoid as a linear servomotor? Those went absolutely no where, and for good cause I now firmly believe.

    Start to think of it as a back and forth discussion, a fully open discussion.

    "...polarized more or less on blame....."

    Not from what I see.

    Look, assuming Toyota has adopted the tranaxle logic that was recommended in 1999 by Sierra Research, and I firmly belive they have, that's all to their credit. A 9.8% improvement in fuel economy is not something to be sneezed at.

    But yes, ultimately the blame lies at Toyota's "feet", no question. Something, somehow, within the engine/transaxle firmware design is flawed.
  • hylynerhylyner Member Posts: 216
    "Start to think of it as a back and forth discussion, a fully open discussion....especially until a solution is found...."
    So far, so good. I could almost buy into that. But then comes your bottom line which flies in the face of the opening comment:
    "But yes, ultimately the blame lies at Toyota's "feet", no question. Something, somehow, within the engine/transaxle firmware design is flawed."
    You also omitted the part which comes before "until a solution is found". One item has to frame that comment,ie "when the problem has been defined".
    Perhaps your premature conclusion is why the "critiques" you suggest always accompany the "back and forth, fully open discussion" are always critiques against anything not laying blame against Toyota?
    Wwest, what you wrote is why I think the solutions side of these discussions are predicated on an heretofor unproven conclusion. That way of doing business is a done deal before any discussion happens. It's made real easy--just blame Toyota--end of story!!
    I may be wrong in a lot of things, but in this case, I know I'm right.
  • scoti1scoti1 Member Posts: 676
    Question -- Who do you think should be "blamed" or be responsible if not Toyota?
  • hylynerhylyner Member Posts: 216
    Well, you could start by learning more about why it affects only a few vehicles and not most others. Is that a design anomaly, a driving style problem, a sensitivity thing, something unique to that particular vehicle, and so on. If it was part of a design thing, then ALL of them should have problems--but that's not happening at all.
    No,don't bother to look elsewhere-- it's a big bad Toyota thing, blame it on a design flaw.
    Then there's a big mystery about the TSB. Why does it apparently work for some and not others?
    Could it be dealers aren't doing it right---or not doing it at all--or some aren't even having it done--or what?
    But no, it's a big bad Toyota thing, blame it on the design flaw.
    I could continue, but why bore you with a search for facts. I'm sure you're not interested, much less want to learn all there is to know about this issue. It's much easier to blame, blame, blame--that's become the predetermined name of this game IMO.
  • scoti1scoti1 Member Posts: 676
    You did not really answer my question. I was asking your opinion of who is to blame. Are you saying that the jury is still out on who is to blame until we know what the problem really is?

    I can concede that it has not been conclusively proven that this is a design flaw nor has it been proven that it is just a quirk in the design related to or complicated by a certain driving style. I would still place responsibility on Toyota -- in either case they are responsible for the "flawed" design or responsible for a design that didn't take into account the driving style of a certain component of their customer base. It is ultimately up to Toyota to take responsibility or to suffer the consequences of not doing so. If their excuse is that it is a driving style problem and only a small segment of their customer base drives in this manner, then it is their perogative to ignore it or offer placebos, but it isn't going to make those folks happy Toyota owners, and Toyota is ultimately to blame for this dissatisfaction. Well, just my opinion. We can agree to disagree.

    Also, it is my opinion that a design flaw can be such that it only impacts a certain percentage of the products or may only be noticeable in a certain percentage. The design has to take many variables into account and ignoring or miscalculating a variable could end up impacting the operation under certain specific conditions. Thus, driving style could be a variable, and ignoring the fact that some people want their car to go when the press the gas under certain conditions could be considered a flaw of the design.
  • shepalishepali Member Posts: 72
    scoti1 - I COULDN'T AGREE WITH YOU MORE!!!!! You have totally hit this nail on the head - dead and center!

    I'm not going to repeat my posts from the other forum here, because it appears it is the same people posting/reading both - so you all will see them anyway. :-)

    In my opinion (and remember, I am one of those people who IS experiencing this phenomenon), this is a design issue that has ignored a segment of the population. And that is definitely their prerogative to do.

    But, in the name of customer service and the Deceptive Trade Practices Act (note, I'm not a lawyer), they should either tell people that their car doesn't perform for everyone, or they should honor a return from someone who is this dissatisfied.
  • wwestwwest Member Posts: 10,706
    for the moment, just a short moment in time, that the fault lies with left foot "brakers". How many firmware designers would have, will have, assumed that the accelerator pedal might be applied hard enough to provide cruising HP and yet have the brake applied?

    Yet we see that exact circumstance on the road every day.

    Were I at the design helm I would disable the DBW anytime the brakes are applied, that would put a stop to that particular aspect.

    But what I'm trying to say is that what if the problem is like that, some unforeseen aspect, a rare one yes, of driving habits that the Toyota engine/transaxle firmware design simply does not provide for.

    And of course Toyota is to blame, has anyone seen any type of disclaimer stating that drivers with somewhat unusual or unique driving habits, such as left foot braking, should not purchase their cars?

    And aren't we all looking to Toyota (who else??) for a solution?
  • user777user777 Member Posts: 3,341
    the solution was creative, but if someone is incapable of connecting an OBD-II interface to capture the phenomenon, we can't reasonably believe they are going to install a new control module.

    and, if you brought a vehicle modded like that into your favorite Toyota or Lexus service shop, do you honestly believe they would work on any aspect of the throttle control, idle or transmission system without majorly bawlking?

    anyway, people modding their vehicles typically are driving Hondas and Accuras aren't they? ;)
  • scoti1scoti1 Member Posts: 676
    And of course Toyota is to blame, has anyone seen any type of disclaimer stating that drivers with somewhat unusual or unique driving habits, such as left foot braking, should not purchase their cars?

    I can see how it would be impossible for Toyota engineers to foresee every single driving style anamoly out there, but when someone is driving as they always have, never had a problem before, then suddenly its a serious problem, yeah, I think some consideration should be given to the buyer.

    Question for Shepali - are you a left-footed braker by any chance?
  • shepalishepali Member Posts: 72
    I follow your train of thought here, and agree that it is a plausible, maybe even probable, explanation.

    But...I am not a a left foot braker - so the particular example doesn't answer what I'm experiencing.

    And, I have been analyzing my own driving habits very closely with all this going on (and, I am an accountant - so analysis IS my job) - and I can not figure out what is so different about how I drive. Having said that - I DO believe that it IS something I'm doing that exacerbates the symptoms.

    I asked my Mother her thoughts (who else could be honest with you about your driving!) - she said that I do drive different than other people. She went as far as to say she's only been in the car with ONE other person that drives like me, and she also said that the two of us are the safest drivers she's ever ridden with. She said that I am always aware of everything around me at all times - so, for example, when I want to change lanes, I don't really even need to look - I just look in order to confirm. So, she said that I do not have any hesitation when switching lanes - where most people do hesitate while they are looking. I had never really thought about all this, but it is a valid assessment.

    I don't have a clue what all that means in relation to the symptoms I'm experiencing - other than I guess I expect a quicker reaction out of the gas pedal than most people? And maybe that constant action, without hesitation, is confusing the car?
  • shepalishepali Member Posts: 72
    scoti1 - once again, I completely agree with your assessment. Thank you for your input and thoughts.

    And no, I'm not a left-footed braker. I actually wondered if it would help though, based on some comments by one of you guys earlier. But, its too ingrained in my head that two-footed driving is a bad thing - and it drives me crazy when I ride with someone, or behind someone, who does it :-)
  • wwestwwest Member Posts: 10,706
    was only presented, used, as an analogy.
  • wwestwwest Member Posts: 10,706
    My 2001 Porsche 911/996 C4 6-speed stick shift is DBW, no mechanical connection between the gas pedal and the throttle plate. The 911 probably has the purest form of DBW, the firmware that monitors the gas pedal position simply drives the throttle plate servomotor into whatever position is dictated by the gas pedal position.

    When I depress the gas pedal on the C4 the throttle plate follows in complete and total synchronization right up until the engine reaches the rev limiter. It is totally and completely my own personal responsibility to be in the proper gear ratio for the acceleration rate that I desire (no lugging the engine) and to coordinate the gas pedal position with the engaging of the clutch.

    The DBW firmware in the Toyotas in question is seemingly different in that it "knows" that if it allows the engine to develop torque BEFORE the transaxle has completed the downshifting into the "most" appropriate gear for the acceleration level you desire then early transaxle clutch failure would probably result.

    And therein is the "RUB".

    The Toyota engine/transaxle ECU DBW firmware has no method, other than the current roadspeed and the current gas pedal position, of "knowing" just what level of acceleration you really desire.

    The firmware controlling these transaxles has apparently been specifically designed to put you into the highest gear possible, 5th with lockup, or maybe even 4th with lockup, at the very earliest time possible.

    That means that any time you release the gas pedal even slightly, and certainly fully released, it will quickly upshift into the highest gear ratio that is reasonable given the current roadspeed.

    But now you suddenly change your mind and depress the gas pedal, possibly just after the firmware has begun the upshift sequence. So the ECU "asks" "just how serious is he/she?", there are at least two possible gear ratios for it to downshift into and given the edict of fuel economy FIRST unless that was a serious "punch" of the gas pedal it will always chose the most conservative gear ratio, say from 5th to 4th.

    In the meantime you have noticed the delay in initial acceleration and human nature dictates that your reaction is to depress the gas pedal just a tad more.

    Oops, says the ECU firmware, he/she really wants to accelerate more rapidly than I first thought! The ECU cannot cancel the previously commanded downshift into 4th, it must now wait for that to complete and then command a downshift into third.

    With each downshift taking on the order of a second or so you may find situations wherein the throttle plate does not react to the gas pedal position for 1 to 2 seconds.

    The above is only a theory of mine but seems to be validated by what I have learned about the transaxle in my 2001 AWD RX300 and the newer 5-speed transaxles.

    Also, there have been indications here and there on these forums that quick and firm, non-hesitant, applications of the gas pedal alleviates the delay symptom.

    My 2001 AWD RX300 exhibits much the same gear changing procedures as proposed by Sierra Research. My 2001 AWD RX300 does not have DBW so during the resultant downshifts the clutch surfaces must endure an unusual level of wear. That is very likely why the earlier RXes are showing a level of premature transaxle failures heretofore unheard of for Toyota vehicles.
  • wwestwwest Member Posts: 10,706
    No, the throttle valve is "sticking" at times I would expect it to do so, during "unexpected" downshifts, times when the transaxle clutches are likely not fully seated and thus there is a need to delay engine torque in order to "protect the drive train".

    Also the dual throttle position sensors and the throttle valve are driven by a common servomotor and were the sensor outputs not to "follow" the commanded movement of the servomotor that would be quickly detected and reported as a major component failure.

    On the other hand since your foot is the "servomotor" the accelerator pedal sensors have no method of cross-checking other than the validity between the two sensors themselves, which, according to the manual is done continually.

    If one of the two sensors was intermittent, occassionally gave a position reading not consistent with its opposite sensor then the ECU would undoubtedly consider that reading invalid and by default, failsafe, "report" the accelerator pedal to be in the "neutral" position.

    It would be anyone's guess as to how many valid readings, contiguously, it would then take for the system to consider the sensors to be giving valid readings again.

    I have no doubt that once an invalid accelerator pedal position reading occurs there would follow a period of defaulting to the pedal being at the neutral position.

    Begins to sound as if it could be the exact thing ocurring, huh?

    Think about this, the accelerator pedal sensor outputs are analog, and therefore must be "read" by the ECU via an A/D, analog to digital converter. Unless some sort of sample and hold circuit is used to trap both voltages absolutely simultaneously, the ECU first samples one sensor and then the other. In the normal scheme of things this occurs so very rapidly that for all intents and purposes the signals are sampled simultaneously.

    But suppose some highly important "other" function (VSC Yaw sensor??) just happens to interrupt the ECU A/D converter sampling/processing between the two samples. "Highly important" because "normal" interrupts would be locked at at this stage.

    In point of fact the industry standard CAN (Controller area network) handling the VSC/Trac/ABS, etc, communications is entirely separate from the Toyota propriatary BEAN (body electronic area network) handling everything else, including the engine/transaxle ECU communications.

    I could readily see that an input from the CAN system would be allowed to interrupt almost any process in the BEAN system.


    Some posters have stated that the symptom often occurs during a turn, a time when the VSC system might be highly active.
  • wwestwwest Member Posts: 10,706
    When you wish to accelerate in the circumstances that often lead to the hesitation symptom, remove your hands from the stearing wheel completely, or be sure you do not move it, the stearing wheel, even the slightest as you depress the accelerator pedal to accelerate.

    There are two primary inputs to the VSC, Vehicle Stability Control, system. A yaw sensor (lateral accelerometer) and the stearing wheel rotational position sensor.

    I'm fairly certain that if you go WOT and enter a tight turn simultaneously you will trigger the VSC system's anti-roll-over firmware routine. That in turn will result in a dethrottling of the engine, at least somewhat, to prevent excessive centrifical force from being developed on the vehicle (top heavy SUV??) to the outside of the turn.

    In trying to think of something just a few drivers might do that triggers the hesitation I came to the conclusion that the stearing wheel might be a clue.

    I had already begun to think the problem might be outside of the Toyota BEAN components and within the CAN components. Therefore it's somewhat possible that a slight "jiggling" of the stearing wheel simultaneously with accelerator depression might result in additional shift decision delay.

    Worth a try?
  • wwestwwest Member Posts: 10,706
    Back in 1999 Sierra Research Inc, an industry consultant to CARB made three recommendations concerning automatic transmission control systems that would likely result in a 9.8% improvement in fuel economy and therby significantly reduced emissions overall.

    1. ASL, Agressive Shift Logic. Assign high priority to upshifting the transmission into the next highest gear ratio as soon, as quickly, as possible given the current roadspeed but without incurring engine knock from lugging due to low engine RPM.

    2. Shift the transmission into neutral at all times with the engine RPM at idle (not enough roadspeed to "drive" the engine above idle) and the brakes applied.

    3. Early O/D clutch lockup. If/when feasible lock-up the O/D clutch in lower gear ratios other than O/D.

    By 2001 Toyota had adopted all three of these measures.

    The problem that quickly developed from that implementation was premature failures of transaxles, especially those that were under slightly heavier duty than normal, Camry transaxle in an RX300...

    So the 2004 and later models use a DBW throttle system to delay the onset of engine torque to "protect the drive train".

    As you coastdown to a full and final stop for a traffic light or sign the transmission will automatically shift into neutral and then finally into low gear as you come to a full stop.

    No problem.

    But if in the middle of that coastdown, and after the system has shifted into neutral, you re-apply pressure to the gas pedal the transmission must be quickly shifted into 1st gear. If you own an RX300 the engine torque will begin to climb before the "downshift" transaxle clutches can fully and firmly seat. If, on the other hand, you have an RX330 them the DBW system will be used to delay the onset of engine torque long enough for the clutches to seat.

    Same goes for downshifting, sudden returns to acceleration, at highway speeds.

    Note that the use of premium fuels are a modified IAT to artificially enrich the mixture would result in a lower engine lugging range, RPM, which would result in alleviation of some instances of downshifting (the engine still has "pull" at the higher gear already in use) and therefore fewer occurrances of hesitation or delay.
  • scoti1scoti1 Member Posts: 676
    wwest, if this is the reason for the hesitation, what, other than switching to higher octane fuel, can alleviate the problem?
  • wwestwwest Member Posts: 10,706
    I wish, truly, that I knew.

    Using the sequential shift mode for those so equipped is the only option I see at this time.

    When I get back to where my shop manuals are located I will see if it is possible to unlink/disconnect the CAN system from the BEAN system to block message packets from the VSC/Trac/ABS/DA/EBD system to the engine/transaxle ECU system.

    These message packets would of necessity have an extremely high handling priority when received by the engine/transaxle ECU and may therefore be the root cause of the hesitation.
  • tedescm1tedescm1 Member Posts: 309
    If this is a real documented problem...why has Toyota continued to market the car with the same problem for 4 or 5 years?

    It just does not make any sense. Is this problem ongoing?
  • scoti1scoti1 Member Posts: 676
    If this is a real documented problem...

    Yes it is real and documented. Problems are continuing to be reported here on Edmunds and other forums. Toyota has issued multiple TSBs to correct the problem in various model years.

    why has Toyota continued to market the car with the same problem for 4 or 5 years?

    Your guess is as good as mine. It obviously does not make economic sense for them to rectify the problem or it is not technically feasible to do so(and still meet emission requirements).

    Is this problem ongoing?

    Yes, it appears it is based on internet reports and continued issuance of TSBs by Toyota.
  • tedescm1tedescm1 Member Posts: 309
    Well if this is an on going problem...i'm not going to join the club. I can't afford a 30k mistake!

    thanks for the info..
  • scoti1scoti1 Member Posts: 676
    I agree with you, but in all fairness, there are a lot of Toyota/Lexus owners who are not experiencing this problem at all, probably the majority. If you have your heart set on a Toyota/Lexus (or any make for that matter) I would recommend taking it on an extra long test drive. Read up on one of the TSBs which lists the different conditions in which this problem is exhibited and try to mimick them. Some other makes have reports of hesitation, also -- not sure if it is the same we are seeing here, but I guess you just need to do your homework. Good luck.
  • hylynerhylyner Member Posts: 216
    Here's another perspective on your question as to:
    "why has Toyota continued to market the car with the same problem for 4 or 5 years?"

    Most participants in ongoing discussions on this issue agree that it only affects a small number of vehicles.
    It isn't exclusive to Toyota/Lexus.
    Other makes and models are reporting the similar issues.
    The problem hasn't yet been fully defined.
    Different symptoms are being reported by different folks.
    It hasn't been going on for 4 or 5 years, and apparently only affects the 5 speed DBW transmission used more extensively in the past two or three years.
    A TSB is out there and seems to work for most but not all owners.
    It is also been suggested that much to do with how some owners operate their cars, as opposed to an electro mechanical issue.
    So maybe it's premature, maybe even incorrect, to suggest Toyota should be tarred and feathered about this issue.
  • scoti1scoti1 Member Posts: 676
    Most participants in ongoing discussions on this issue agree that it only affects a small number of vehicles.

    It is more accurate to state that most of us agree that it is difficult if not impossible to quantify the number.

    It hasn't been going on for 4 or 5 years

    The first reports I find (and first TSB) date back to the 2002 Lexus models. I have read of hesitation reports in 2006 models. That means it has impacted 5 model years.

    affects the 5 speed DBW transmission used more extensively in the past two or three years

    This seems to be correct. It could explain why it has taken so long to address. It may have not seemed like a big issue until more and more models were being affected.

    A TSB is out there and seems to work for most but not all owners.

    It has worked for some, not for others. There is nothing to quantify the numbers or to even lets us make a statement that it "seems to work for most" unless you are working for Toyota and know the actual numbers.
  • hylynerhylyner Member Posts: 216
    Different folks have different opinions. Brinkmanship isn't the answer.
    So, as I said, "maybe it's premature, maybe even incorrect, to suggest Toyota should be tarred and feathered about this issue".
    So perhaps we shouldn't do that just yet. ;)
  • wwestwwest Member Posts: 10,706
    Maybe not tarred and feathered, but certainly to be avoided until they are able to widely and publically announce a sure and certain solution.

    Haven't I seen posts indicating no hesitation problems for 30,000 miles and then suddenly??

    Until the root cause is widely known and therefore the delay can be readily duplicated it is definitely best to avoid Toyotas or Lexii with 5-speed transaxles, FWD or front torque biased AWD.
  • hylynerhylyner Member Posts: 216
    Tarring and feathering and advocating avoidance are synonymous. One is merely another version of the other.
    No matter how it gets sliced and diced, those actions are nothing more than two examples of vigilante justice in its many disguises.
    Condemnation on the basis of what is mostly speculation for any issue is clearly wrong, and perhaps even irresponsible.
    Sure, opinions are one thing; everyone is entitled to them.
    However, when a "Ready, Fire, Aim" philosophy is introduced, it's a pretty good indication the intent is to steer the issue in the wrong direction.
  • scoti1scoti1 Member Posts: 676
    wwest, you have immersed yourself in this issue more than anyone who participates in these forums. I respect your opinions. However, while I personally won't buy one of these vehicles until the issue has been resolved to my satisfaction (I have a feeling I will buy something else before that happens), I am not to a point where I would tell others not to buy one. I do think anyone buying one needs to do so with eyes wide open and be willing to accept the consequences should the hesitation problem arise. What I would say is, if you can't live without owning a Highlander, Camry, Avalon or other affected model, then do your homework, do extensive test driving, and be aware that the problem could still crop up later. BTW, I don't recall reading about somenone not experiencing the hesitation until 30,000 miles. Wow!
  • wwestwwest Member Posts: 10,706
    The analogy I would use would be like playing russian roulette. Buying a transaxle based Toyota/Lexus today would be much like playing russian roulette with ~1,000(*) empty chambers and one bullet.

    * Insert the ratio of your choice.

    The ratio may be lower or higher but the facts indicate that some significant(**) percentage of buyers, including 2006 models, will encounter the transaxle downshift delay symptom.

    ** Toyota is still issuing new and/or revising old TSBs to address this "problem".

    The fact that MY2006 customers are also reporting the problem should be a clear indication that the final solution is not yet available.
  • scoti1scoti1 Member Posts: 676
    The fact that MY2006 customers are also reporting the problem should be a clear indication that the final solution is not yet available.

    "45. Just drove two examples of 2006 ES 330 at the Taste of Lexus event in Dallas and both had the hesitation problem reminiscent of newly computerized cars of the early 80s. Hopefully, Lexus will solve this very annoying problem with the brand new 2007 model due out in the Spring of 2006.
    Posted at 10:58AM on Nov 9th 2005 by Kgm"
  • scoti1scoti1 Member Posts: 676
    Hylyner, I was trying to refresh my memory on what model Toyota you owned and went to your profile which states:

    Vehicle #1: 2004 Toyota Sienna
    Vehicle #2: 2002 Toyota RAV4

    But your first post in the Engine Hesitation forum, which was your first post as a Edmunds member, back in October '05 states:
    "#2005 of 2421 Can You Give The Rest Of Us A Break? by hylyner Oct 12, 2005 (5:22 am)
    Bookmark | E-mail Msg
    There are two Toyotas in our immediate family, both Highlanders, one new. "

    Did you get rid of the Highlanders for the Sienna and RAV4? Can you clarify? Just wondering what kind of Toyota(s) you are driving and why you dumped the Highlanders if that is what you did.
  • user777user777 Member Posts: 3,341
    remember the other forum got shut down because of goating and resulting devolution into personal tete-a-tete / point-counter-point.

    allow hylyner to post at will. other people can judge for themselves if someone has a hidden or overt agenda or not.

    let's keep this discussion of a "technical" nature to meet the requirements imposed recently in the other forum.
  • hylynerhylyner Member Posts: 216
    There are now THREE HLs in our immediate family. We traded the '02 RAV4 for an 06 HL last month. No.1 son bought an 05 in July 05. No. 2 son has an 03. We bought ours because theirs were excellent vehicles.
    None of them exhibit the hesitation you refer to.
    My wife still has the Sienna, and it's not having any problems either...
    Would a signed affidavit give ye of little faith more peace of mind? :P
  • scoti1scoti1 Member Posts: 676
    Yeah, sorry about that. Not even following my own advice.
  • bettersafebettersafe Member Posts: 92
    I have enjoyed following this discussion for months. I am often reminded that the hardest problem to fix is when there is more than one problem!

    What intrigues me is that some drivers have serious concerns about the transmission, and some drivers do not. I would like to know why that is so.

    Has anyone come up with a matrix of possible causes, and then try to sollicit the people who have problems to fill out a "possible cause" questionnaire? For example, the questionnaire might indicate that folks who use Gasohol are more likely the have the problem than folks who do not burn gasohol. Folks who burn premium may have less problems. People who have replaced their transmission fluid in the past "X" miles may not have the problem. How many people have checked their transmission fluid level when trany was cold. How many people have checked trany level when hot. People that start their car and let their car warm up for 60 seconds with no pressure on the gas pedal might have fewer problems. Drivers with a lot of stop and go driving may have the problem more than those with constant driving speed. A person who drives very lightly on the gas might have more problems than a heavy footed driver. A person could probably come up with 100 possible correlations. The survey might help identify the common threads that are associated with folks with problems - and - show the common threads of folks who do not have problems.

    I am also a bit surprised that no-one with the problem has linked up with someone with a compatible OBD diagnostic tool. If it was my car with the problem, I'd find a mechanic to help me define the problem with hard data.

    As it happened, I recently purchased an Hyundai XG350 rather than an Avalon for reason of the comfort of the seats (wife has a bad back). We did not notice any shift problems in the Avalon that we test drove. The XG has DBW, but it has a totally different shift algorithm from the Avalon. As you slow down to make a turn, it will downshift to be ready to scoot out of the turn. It does not upshift to maximize MPG. And, not surprizingly, the XG gets lower MPG than the Avalon.

  • hylynerhylyner Member Posts: 216
    "The hardest problem to fix is when there's more than one problem"

    Many thanks for your refreshing outlook on this issue. Your comments underscore much of what I've been talking about all along, namely, define the problem first, then go about developing solutions.
    These folks have been "immersed" (as one stated)in searching for solutions for a long, long, time.
    A solid definition of the problem and all its manifestations hasn't happened, and I'm convinced the solution likely won't ever happen here either.
    I honestly believe if half that time had been spent looking at the issue by researching correlations as you suggest, a solution (or perhaps solutions!!) would have appeared on the scene long ago.
    I sometimes find myself wondering if solutions are really the objective after all.
    Your post answers a ton of questions, and clearly illustrates wher the problem truly exists in this ongoing quest for a solution.
    I'll add one other truism to your opening statement:

    "We work diligently looking for solutions, but merely create more problems."

    One more thing--I'm certain you'll be happy with your Hyundai. They have really raised the bar during the past few years.
  • user777user777 Member Posts: 3,341
    i think part of the problem with that approach is that people have different language to describe similar, and as you point out, probably different phenomenon.

    the point you re-iterate that i feel would be more helpful than any other avenue discussed thus far would be for someone with a repeatible and significant issue to purchase an OBD-II interface that can capture the toyota specific parameters that could show us all (hopefully - remember, it's not a sure thing), objectively what is going on with their ride as they repeat the hesitation a number of times.

    this would allow us to see what is going on, and converse about the actions of the "system", human / machine in a more informed and less ambiguous manner.

    the price of a reader capable of interfacing to a laptop and capturing data in real time is on the order of $125.00. i've already posted the link for a compatible device with the feature set i would expect appropriate to attack this experiment. anyone can find my prior posts, but if necessary, i can post it AGAIN.

    if someone wanted to venture into the enterprise and since i'm personally interested in the results, i would be willing myself to offer 1/5th of the cost of the device to the person who has the issue, has a laptop and is willing to invest some time and effort trying the experiment a few times as deemed necessary.

    i personally could be convinced to offer up more. we'd probably have to do some test runs, and potentially toss the results if more or different parameters are needed.

    so my $25 is on the table as a most sincere offering to move this issue and our understanding forward.

    how about you other posters and/or forum readers out there in automotive ether-land?

    geesh - i personally believe this is something Edmunds should be doing because of the attention the webset would receive if the experiment helped pinpoint the problem...of course, they may be hesitant to possibly place any potential advertiser or manufacturer in a tough spot... (yet who's the biggest and best automotive advocate we know?). ;)

    you'd think (i do anyway) that the hosts would have killed it by now amongst themselves as a friendly personal bet, but no joy.

    aside: edmunds should have an automotive investigative team of EXPERTS (or fund an independant team of EXPERTS to prepare a report on a matter like this) that from time to time goes after needling problems.

    maybe when they get a little bigger perhaps? ;)

    so reality what it is, collectively, we have to take it upon ourselves to invest the time, the money and the effort to *try* scientifically and more methodically to get to root cause of the problem.

    theorizing is interesting, but it's getting no one with the problem any closer to resolution and satisfaction in their driving experience.

    we need to identify an owner with the problem willing to work with us, who has access to a laptop, and who is or knows someone moderately computer savvy.

    we need to identify a few other posters willing to ante up some green here.

    we need a few people to review the normal / generic OBD-II parameters, and Toyota/Lexus specific paramters and help identify the parameters we want and need to collect, and design the experiment.

    i'm all for it. anyone else with me?

    think about this: remember the aside above?

    ok - think about a small team of average joes and joans willing to do this. regardless of the outcome, don't you think the experiment itself written up and posted on Edmunds would be of interest to other Edmunds and automotive domain readers. ohhhh, if they aren't willing, perhaps we send it to an automotive magazine, and/or a newspaper?

    it could be the start of a trend...consumers willing to invest their time money and effort to help manufacturers deal with design issues impacting customer satisfaction.

    no guts, no glory.
  • hylynerhylyner Member Posts: 216
    Y'know user77,it sounded like 'deja vu all over again' when you and Scoti did that "let's ignore--he's a shill" inference one more time, but I was greatly encouraged by your comments this morning.
    What you said in your post really lends credibility to what I've tried to say all along.
    It certainly goes along with what Bettersafe and I just talked about.
    Please understand and try to accept that I do not have any sort of hidden agenda. On the contrary, I believe I've been up front right from the git go in trying to get the focus in this issue pointed in the right direction. Nothing has been 'hidden', so I would greatly appreciate it if you would stop treating folks like me as adversaries.
    I have never tried nor do I intend to discount the many technological theorizings that's been a big part of these discussions--they have, for the most part, been quite educational and informative. All valuable background stuff which at some point may turn out to be very useful.
    The ONLY thing I take issue with is that this entire discussion focusses blame on only one entity, and that verdict was reached arbitrarily.
    In other words, you chose a solution by suiting your own interpretation of the (very) little information available.
    That said, maybe we could start by listing what is known, and then list what remains to be known---and when that's done (and done thoroughly), we could start thinking about solutions.
    What do you think??

    PS. I've got the guts, but rest assured I'm not looking for any glory!!
  • scoti1scoti1 Member Posts: 676
    I think your idea is just fine. However, I can see how Edmunds may not want to be associated with performing the testing. I can also see that Toyota may not be appreciative, as I think you are implying. I think after 5+ years of dealing with this issue, Toyota knows exactly what is wrong and exactly how to fix it. It is my opinion that they aren't fixing it because it is a. too costly or b. would result in compromising some other aspect of the vehicle's performance (fuel efficiency? pollution standards? other?)
  • hylynerhylyner Member Posts: 216
    "I think .....Toyota knows exactly what is wrong and exactly how to fix it. It is my opinion that they aren't fixing it because it is a. too costly or b. would result in compromising some other aspect of the vehicle's performance (fuel efficiency? pollution standards? other??)

    Scoti, I realize that's your opinion, and accept that you're entitled to it.
    But it really doesn't speak to a practical solution, nor does it speak to objective and factual research which might lead to a practical solution (or solutions).
    I think User77, Bettersafe, and (Heaven forbid!!) yours truly have perhaps suggested a more practical approach.
    Would be interested in supporting something like that??
    Perhaps even go along with it?
  • scoti1scoti1 Member Posts: 676
    There has been suggestion by Toyota that premium fuel could improve performance. I did a search of the Transmission problems with Lexus forum and found that several noted some improvement when switching to premium fuel (althought it doesn't sound like the problem went away) and one owner reported worse performance with premium fuel. Here are the links:

    Premium gas issue

    es4jb, "Transmission problems with Lexus ES-300 ?" #841, 18 Nov 2005 4:27 pm - States that the car performs better with premium gas.

    snaab93se1, "Transmission problems with Lexus ES-300 ?" #819, 5 Oct 2005 4:27 pm - States that car performs worse with premium gas.

    beardie, "Transmission problems with Lexus ES-300 ?" #766, 28 Jun 2005 11:58 am - Told by Lexus that one must use premium after having TSB perform to get proper performance.

    dgoodrow, "Transmission problems with Lexus ES-300 ?" #538, 9 Aug 2004 1:43 pm - some improvement with premium fuel.

    toydriver, "Transmission problems with Lexus ES-300 ?" #269, 18 Nov 2003 12:48 pm - some improvement with premium fuel.

    greggba, "Transmission problems with Lexus ES-300 ?" #247, 13 Nov 2003 5:45 am - Performs better with premium fuel and multiple passengers.
  • scoti1scoti1 Member Posts: 676
    Some more from the read-only Engine Hesitation forum:

    05camry33se, "Engine Hesitation (All makes/models)" #2130, 30 Oct 2005 6:15 pm , 05camry33se, "Engine Hesitation (All makes/models)" #2129, 30 Oct 2005 5:28 pm - Switched from premium to regular and did not notice loss of performance.

    mert2, "Engine Hesitation (All makes/models)" #1379, 1 Aug 2005 1:46 pm - No improvement with premium fuel.

    shaweet, "Engine Hesitation (All makes/models)" #1372, 31 Jul 2005 11:28 pm - using premium before TSB did not improve performance

    jaegerlou, "Engine Hesitation (All makes/models)" #72, 12 Jan 2005 1:47 pm - No improvement with premium fuel.
  • scoti1scoti1 Member Posts: 676
    Some more...

    “I have always used premium as well, but I have seen the hesitation issue quite a bit. Usually when I am navigating through a parking lot. “

    coordo, "Toyota Sienna Owners: Problems & Solutions (2003 earlier)" #3355, 18 Aug 2005 4:21 am - improvement with premium fuel.

    larrymit, "Toyota Camry Owners: Problems & Solutions" #3619, 18 Jul 2005 9:37 am - improvement with premium fuel.

    globeguy, "Toyota Camry Owners: Problems & Solutions" #3306, 4 May 2005 7:09 am - improvement with premium fuel.

    solara00, "Toyota Camry" #7551, 4 Mar 2005 8:25 pm - Improvement with premium fuel.

    cyclone4, "Lexus LS" #5735, 13 May 2004 7:10 pm - No improvement with premium fuel.

    kybill, "Toyota Highlander" #8349, 22 Jun 2003 5:17 am - improvement with premium fuel.
  • wwestwwest Member Posts: 10,706
    Toyota yet knows the solution...

    The VSC/Trac/BA/EBD system uses the industry standard CAN, Controller Area Network, for communications between ECU nodes while the other ECU nodes use the BEAN, Body Electronic Area Network, likely propriatary/unique to Toyota or NipponDenso.

    I have begun to suspect that the problem lies between interaction between the two systems, say for some reason the BEAN system thinking the CAN's VSC is asking for dethrottling.

    In any case if it is some sort of interaction between the two network system controllers that might make it extremely difficult to troubleshoot.

    Think of this...

    Just prior to any downshift it's likely the engine/transaxle ECU must send a packet via the BEAN's packet communication system through the BEAN/CAN gateway to determine the appropriateness, of not, of a downshift.

    For instance just before coming to a full stop with the brakes applied the transaxle will likely be in neutral. If ABS or VSC is currently active then a downshift should definitely be delayed.
This discussion has been closed.