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Transmission problems with Lexus ES?



  • I have had my '02 for 6 weeks (34,000 miles on it) And I have not experienced any of the hesitation issues I have been reading about here.When I hit the gas from a stop or at 15 MPH the car takes off. I had an 01 ES and an 01 Maxima and this '02 ES accelerates just as quick. I have only used 87 octane. I did drive 2 '06 ES loaners and I did notice a lag in the response when hitting the gas. My car was first registered in June '02, maybe the early prod vehicles do not show signs of the problem.
  • wwestwwest Posts: 10,706
    You don't say which your '02 is but the problem only exists, seemingly, with the V6/5-speed.
  • I have the 5 speed auto v6,2002 ES300 - isn't that the only engine available ??
  • billranbillran Posts: 113
    I believe so. It would seem that out of 2,000,000 cars Toyota produced with that drivetrain used on various models for the last four years, only a very small percentage of owners actually report that they detect hesitation. Like me, you have one of the many vehicles that drive great. Enjoy!
  • I actually have read all the posts on this board, as well as a good portion of them on the Engine Hesitation forum that was closed, and the new forum that looks like it was closed too. I did spend many, many hours reading all of them, and found them very helpful. I did see texas83, and I am actually in Texas myself, so was quite discouraged by their results.

    I guess I am a glutton for punishment - that I decided to try anyway - but that's all I've gotten so far, is punishment.

    But, I'm still trying. Talked to the Lexus area office today, and we're trying to work something out right now. I'm not too hopeful, because it sounds like a whole bunch of what I've already been hearing....but we shall see.
  • I'm not sure I follow....
  • wwestwwest Posts: 10,706
    That's okay, I think that "road" was a dead end anyway.
  • shepalishepali Posts: 72
    Well, I haven't had time to read the 150+ new posts on the other board that got closed since I was last there...hope to get to that in the next few days.

    But, thought I'd give those of you who are left reading about this topic, an update on my saga...

    My written complaint/demand to the Lexus Manufacturer (which was a prerequisite of my Lemon Law claim, per my state's laws), has actually piqued some interest. Lexus has made me an offer to buy back my car, and sell me a new Lexus of my choice. I am in the process of evaluating the numbers they gave me to see if its an acceptable deal for me....

    Will keep you all posted - in the mean time, the car is just sitting in my driveway collecting dust :(
  • scoti1scoti1 Posts: 676
    Well good luck. If you get in another Lexus you need to test drive the heck out it to make sure it doesn't have the same problem since Lexus/Toyota obviously hasn't fixed this yet. Or maybe go for a model that doesn't have the 5-speed DBW.
  • wwestwwest Posts: 10,706
    The RWD models, seemingly, do not have this problem. Apparently at least not at the unsafe or hazardous level of 1 or 2 seconds that are more common to FWD or front biased AWD models.
  • atoewsatoews Posts: 637
    Depending on how much you can get for your car, this sounds like the best deal from among those received by any poster to date. Of course, I doubt you want a new 330/350 and the other models are significantly more expensive.

    Good luck.
  • shepalishepali Posts: 72
    I'm evaluating the GS and the GX. Two TOTALLY different vehicles, I know. For those that have followed my posts, you've heard me say that I may actually be bipolar - this may confirm it :D

    I had read somewhere on this forum about the GX having a gear hunting problem at highway speeds, in cruise control. I briefly experienced it on one of my test drives. Do any of you know if that is as prevalent as the ES issue? Is it related at all?

    As for the GS - I believe it's RWD - right? I haven't been able to find many complaints about anything mechanical with that vehicle. I haven't test driven it long enough either. Any input?
  • wwestwwest Posts: 10,706
    The GS300 is now available with an absolutely STELLAR AWD system, something us RX300 owners can only dream about. The GS350 uses the new DFI engine and is only available as RWD.

    "Life" for designers of the firmware for shifting control of automatic transmissions has gotten super complex in the past 2 or 3 years. More gear ratios, more torque converter lock-up modes, more sensitive knock sensors and now DBW, e-throttle.

    The 5-speed transaxle now has at least 7 forward speed modes, maybe even eight. The lock-up clutch in the torque converter will often be engaged in other gear rations than O/D. Third and O/D even in the 4-speed transaxle in my 2001 RX300.

    So yes, it is very likely owners of 5-speed and the new 6-speed automatic transmissions will sense a lot of extra gear hunting as the ECU continuously "hunts" for the best gear ratio given the current circumstances. During cruise, especially with cruise control engaged, fuel economy will in all likelihood be the single highest priority for the ECU's decision making insofar as gear ratio is concerned.

    Therefore it will be quite heavilly biased toward being in, remaining in O/D and lockup as long as conditions allow. But then approach/reach the "slightest" of inclines and the ECU will command a shift out of overdrive and disable lockup. If the incline now has a constant slope for a distance then it will likely relock the torque converter in the lower gear for most of that distance.

    But no, the gear hunting will not likely be as prevalent as the ES series. Any FWD vehicle is more subject to loss of control if the ECU commands a downshift that results in an undesireable level of engine compression braking. The ECU has no "sense" of the possible slipperiness of the roadbed so it must, by default, avoid high levels of engine compression braking at all times.

    Obviously that adds an extra decision "node" to the engine/transmission shift control firmware.
  • shepalishepali Posts: 72
    I finally got through the 150 or so posts that happened in the last 10 days or so of the other forum that was closed. And I'm really sorry I missed all the discussion (although, I could have done with out some of it, of course!! :blush: ).

    But there were some great points and suggestions brought up in those posts. As someone who is experience EXTREME displeasure with my ES, I think that the discussion about the accelerator pedal position and braking interaction has some strong merit. My challenge is that the accelerator does not respond like I'm used to, nor how I would expect. This causes me to 'flutter' (for lack of a better word) the gas pedal WAY too often - it actually annoys me how much I have to do this. Then, the car doesn't decelerate when I release pressure from the accelerator (either partially or fully), which causes me to use the brakes WAY more than I am used to, or want to (it is my opinion the brakes should ONLY be used when stopping, I mean, I think the car should slow down when you release the gas pedal and if you plan accordingly, then you wouldn't need to use the brakes unless you needed to stop - albeit in an ideal situation). This back and forth from the gas to the brake seems to cause the symptoms I experience (actually, thats HOW the Mfr Rep was able to duplicate my symptoms - strongly on the gas, followed by strongly on the brake, over, and over). How that plays into the VSC - I don't have a CLUE! My non-engineering thought is that its not related - because I've never felt like the brakes were being applied as someone described, and because most of my problems are at slow maneuvering - so its not like the car should think it has lost stability. But I also admit, I don't understand all that technology - I'm just going on 'feeling'.

    Another thing I don't understand is the notion that the memory is completely erased every time the car is turned off - even the dealer told me that the memory feature takes about one week to 'learn' your habits, so that doesn't reconcile. Also, my husband does experience the symptoms in my car - which we assume are caused by my habits being learned by the car (I suppose maybe it could be that he has the same habits - but of course, he disagrees with that concept! :D ).

    By the way - I am totally willing to answer your series of questions, I'm just not here on the board often enough to make it useful apparently (since someone said no one was respondng...). Is there a way to do that off the forum - so we don't bore or upset others?

    I also completely agree that this is not a widespread problem, and that most people do not experience the same symptoms as I do. But my feeling is that shouldn't matter - even if it was only ONE person that was having such a horrible experience as I am (and I think it is obvious that there is definitely more than ONE), my opinion is that a dealer and/or manufacturer should work with that person to get them into a car that DOES work for them - that's called customer service and the 'pursuit of perfection' (or whatever the Lexus slogan is).

    Anyway, I think that after enough complaining and threats, I have finally gotten somebody's attention - it appears that the manufacturer is finally willing to work with me. And at that - I have not even been asking for some exhorbidant compensation. All I have EVER been asking for is that they get me out of my car at no profit to them. They made plenty of profit when I bought the car (I didn't negotiate it very well!!) - and they should be able to sell it to the majority of the population who doesn't experience this problem for another profit. So, I don't understand why they were not initially willing to work with me on this, and why it took such a painful time consuming effort on my part to achieve what I think as a reasonable request and solution.

    Anyway, thank you to all of you that have offered suggestions, possible solutions, and all of the technical information provided. It has really helped me to understand the problem, and to be able to explain the problem to others (albeit, in not as technical of terms as WWEST uses ;) )
  • shepalishepali Posts: 72
    I have a business acquaintance who has the EXACT same car as me - same model, same year, and even the same color! She actually purchased it around the same time that I did, as well. I recently asked her if she was experiencing any of the problems I have. At first description, she said no - that she is very happy with her car. When I went on to explain what I have figured out and what I have learned from the dealer and here from all you techies - such as the DBW technology, the fuel economy technology that switches the car into neutral and/or a higher gear based on the gas pedal position, and the clutch protection feature that causes a delay when it does switch to the proper gear - she had a light bulb go off. She said there is, in fact, ONE time and place where she does experience what I described. She said it is when she is pulling into her subdivision, which requires a left hand turn on a very busy street. She said that the car has a hesitation when she hits the gas pedal to cross the traffic - and that is is so severe that has learned she needs to wait until she has a longer distance between her and the oncoming car before she will pull out (which she also commented does not make the cars behind here very happy :) ). Interestingly though, she said this intersection is the ONLY time and place she has ever has this happen - and that she had learned to adjust to it such that she didn't even realize it was an 'issue' until I described it to her.

    It makes me wonder if now that I have brought her attention to it, that she will start to notice it in more places and times. I hope for her sake, that does not happen!
  • wwestwwest Posts: 10,706
    I would ask your friend to try, a few times in a row, at that point, intersection, coming to a full and complete stop before trying to surge into or across traffic.

    I believe the shift into neutral occurs shortly before coming to a stop and then the transaxle will actually shift into 1st ONLY AFTER, when, you have come to a full and final stop. If you try to accelerate prior to that full stop that's where the "delay" occurs.
  • wwestwwest Posts: 10,706
    There are two types of parameters the various ECUs in your vehicle must learn, and sometimes re-learn on the fly as certain devices, especially mechanical devices, parameters change over time and use.

    And yes, one set will be unique to each individual driver, while the other set will be unique to the vehicle itself.

    For instance my suspecion of the moment is with regards the accelerator pedal idle, fully released position, sensors voltage output.

    The manual states that if this assembly is replaced then it must be left in the idle position for at least 15 seconds after, once the battery is reconnected. While there is no explicit statement saying that the ECU is "learning" the sensors' idle position output voltage during those 15 seconds I assume that is exactly what is happening. Additionally the manual does say that the differential voltage between the two pedal position sensors can vary over a fairly wide range the system "learns" the actual voltage value and then uses that learned value to check the primary sensors output voltage/position for validity.

    Additionally almost all of the devices that require "learning" have tolerances regarding long term drift. So the ECU must constantly monitor the sensors for this "drift" and adjust the stored parameter accordingly.

    So, the battery gets connected and the ECU, within 15 seconds, has learned and stored the exact/explicit voltage value that represents the accelerator pedal being at idle.

    Note that if, by happenstance, something is laying on the accelerator pedal at this time it is likely the wrong value will be stored. But let's assume that whoever reconnected the battery assured that the pedal was actually fully released.

    Now all the ECU need do is concern itself with any possible drift over time, use, or wear. And let's suppose that the way it does that is to check the pedal sensors' output voltage each time the shifter is moved from the park position, wherein the brakes must be firmly applied.

    And let's further assume that if the voltage it reads at that time widely varies from the previously stored idle position value. In that case the new reading would be likely to be discarded as being invalid.

    But what if one of the drivers, maybe the most common driver, has a habit of ever so lightly depressing the accelerator pedal time their left foot is used for the firm braking needed to release the shifter.

    Mighten, in that case, the parameter for the accelerator pedal drift away from the initially stored value as time passes?

    What happens if so?

    Maybe we can find out.

    Many of you are not having, experiencing, any indication of this inordinate delay...

    Would someone in that "class" please try the following.

    Disconnect the battery and before reconnecting it have some one hold the accelerator pedal down, maybe about 1/4 of the full travel. While the pedal is being held in this position reconnect the battery and continue to hold the battery for the required 15 seconds.

    The ECU should have now learned that the accelerator pedal idle position is actually 1/4 of the pedal's full travel. That should mean that you must depress the pedal at least 1/4 of the travel before the engine RPM begins to rise.

    And now the base question is whether or not the ECU will learn, readjust, the false learned battery after a few days of use and what the engine/transaxle will act like until it relearns the true idle position.
  • shepalishepali Posts: 72 this theory in line with whoever said in the other forum (maybe it was you?), to not use the brake or gas pedal when starting the car, or for 15-30 seconds after the car is started?

    I know for sure that I put my foot on the brake whenever starting the car - just plain habit from drivers ed, and driving stick shift. I keep my foot on the brake until I put the car in drive/reverse. At home, I back out of the driveway immediately, then put on sunglasses, set my navigation, wait for the garage door to close, etc.... Anywhere else, I may do those things before I put the car in gear - but most likely, my foot would be on the brake the whole time...

    Are you, or someone else, suggesting that this procedure MAY have some impact on the symptoms the car is experiencing?
  • shepalishepali Posts: 72
    After reading all those messages in the other forum yesterday, I've really spent some time thinking about this....all while driving my Suburban :shades:

    I really do believe that these 'habits' I supposedly have that are affecting my car, are related to the interaction between the gas pedal and the brakes. This is also supported by the fact that I experience the symptoms most severely in slow maneuvering, and heavy traffic - two times where you are on/off the gas/brakes. Coupled with the fact that when the Lexus Mfg Rep was recreating the problem in my car, thats exactly what he did to generate the symptoms - albeit, in an abnormal fashion.

    I was trying to explain last night that the gas pedal on this car does not allow you to control the deceleration of the car - when you release the gas pedal, it upshifts or shifts into neutral, and therefore coasts rather than slows down through engine braking. Then, when you have to use the brakes, it further supports that you must want to be in neutral - then when you hit the gas again, it is confused by what you are asking it to do, causing a delay and then shift-shock when it does figure it out.

    I don't know how that exactly plays into everything you engineers are describing...but I hope it helps you guys figure it out - at least for Lexus's sake :)
  • wwestwwest Posts: 10,706
    Which foot....?

    My supposition is that if you brake with your left foot in order to "trip" the release for the shifter while "resting" your right foot on the accelerator the ECU might be fooled into storing the wrong idle, at rest position for the accelerator pedal.

    For instance I was totally surprised to discover that somehow I have developed the habit of using my left foot for braking when backing out of the garage each morning.

    Until I came to that realization just last week I would have been willing to bet that I always used my right foot for braking.
  • user777user777 Posts: 3,341
    shepali: one more time, this was the experiment i was proposing if you are having the problem:

    with both feet on the floor mat: turn your key to ACC position but not all the way to engage the starter. wait about 5 seconds for the pump to put fuel up to the injectors.

    start the vehicle but do not use the accelerator or the brake.

    wait with both feet still on the floor mat 10 seconds.

    put foot on brake and shift out of park.


    report if the behavior of the vehicle is any different than before.


    look wwest: you don't need to disconnect the battery to do this novel test you're proposing. the ECU *probably* performs a recal of the "zero accel" on each start. both of our tests are to prove that theory and the extent to which it may influence vehicle operability.

    for your test, have shapali try this experiment too:

    car is off.

    put a bit of pressure on the accelerator, and with the other foot put your foot on the brake. hold steady.

    start the car. hold steady for 5 sec.

    now take your foot off the gas, engage reverse.


    report behavior.

    do either of the experiments require refinement?
  • wwestwwest Posts: 10,706
    I do not, cannot believe, that the engine/transaxle ECU will "accept" a totally new, highly disparate, idle position sensor output voltage absent being forced to start from scratch.

    Remember an earlier experiment carried out by bkinblk?

    Disconnecting the battery each and every evening eliminated, seemingly, the hesitation symptom.

    I agree that your methodology would work, but I suspect only over multiple drive cycles, maybe as much as two weeks.

    My current theory is that whenever the idle value stored voltage was first "recorded", it was likely correctly done. Battery reconnected while the accelerator pedal was, truly, at the fully released position.

    The ECU firmware MUST have the ability to compensate for sensor variations that will occur over time, useage, wear, etc.

    But no programmer in his right mind would accept a sudden large variation in the sensor output without raising a question, a CEL most likely.

    On the other hand if the variation were within the tolerance, margin of error, the parameter variation would likely be accepted, at least over multiple drive cycles. If the variation were not large enough to trigger a diagnostic, but consistent from drive cycle to drive cycle, the stored value might "creep" up to the wrong value.

    If I am correct, and my theory IS well founded, it would again take multiple drive cycles to move it back to the true idle value.

    And we not only have the earlier bkinblk experiment as validation, we have all the posters who tell use the TSB seemed to help at first but then the system "regressed" to its old ways.

    I have no doubt that a part of installing the TSB involves "wiping" the ECU memory.

    So, should anyone wish to try your method may I suggess a modification? Disconnect and then reconnect the battery while being sure the accelerator pedal is at the the fully released position, and remains there for at least 15 seconds.

    But my focus would still be only on the exact moment the shifter is moved from park. The firmware designers would know, could be CERTAIN, that the brake is firmly applied at that time. Who, amongst us all, would INTENTIONALLY have any level of pressure on the accelerator pedal during that sequence?

    But unintentionally or inadvertantly..??
  • shepalishepali Posts: 72
    As mentioned in my previous posts, I absolutely do not ever use my left foot for braking. I have a complete and total aversion to the concept - and further can not stand those who do drive that way, both when I ride in their cars and when following them on the roads.

    Sorry - but that's not it.
  • shepalishepali Posts: 72
    I still don't really follow everyone's engineering talk...but here's another potential link for you guys to pontificate over :)

    I remember previous posters here complaining about a 'surge' when they first put their cars in gear. I also experience this surge, but never really found it annoying or dangerous - its one of those things I just learned to adapt to. I always assumed it was just the car idling higher due to being cold, so when you put it in gear it had more gas and thus 'surged'.

    But...your thoughts about this start up procedure and the gas pedal makes me wonder if there is some relation. Maybe its not, but thought I'd give you more to think about :D
  • scoti1scoti1 Posts: 676
    I am not a left foot braker either and also hate following those who do. But, when wwest described that his driveway is on a slope and sometimes he has his left foot on the brake when he first starts the car and eases into reverse, I realized that I do the exact same thing sometimes (my driveway also has a steep downslope and when my wifes car is right in front of mine I left foot brake to keep from rolling downhill into hers -- it will roll forward in the time it takes for me to get my right foot from the brake to the accelerator, so I must use the left foot to brake to keep this from happening). So when wwest asks about left foot braking upon start-up, this is what I think he is talking about.
  • wwestwwest Posts: 10,706
    Yes, the specific point, time of interest, is when you shift out of park. You MUST have the brake firmly applied in order to shift out of park and I'm asking that you be SURE your right foot isn't resting on the accelerator pedal as you follow that procedure.
  • ruby1ruby1 Posts: 8
    I'm one of the many people who have hashed it out with Lexus (Regional Manager, Dealership, Corporate office etc)about the hesitation in the transmission (ES 330 2005 model). Lexus was very unhelpful in getting me out of my problem. They offered me 28,500 to sell it back to them with 3,000 miles on it. It's fully loaded and cost 38,000 with taxes etc.
    My father has the same make and model and has never had a problem with the car hesitating. His secret ... 93 octane gas. I was using the suggested octane (89) from the day I bought the car. I switched to 93 octane two months ago and I haven't had the car hesitate since. In fact, the car now has incredible pick up, engine noise is barely noticeable and the car flat out hauls on the highway now. :shades:

  • wwestwwest Posts: 10,706
    "...adjusts to the primary driver....."

    Is that why we never see any Toyotas in the rental fleet?
  • scoti1scoti1 Posts: 676
    Here is a link to a post from the Avalon 2005+ forum:

    alan_s, "Toyota Avalon 2005+" #11557, 8 Mar 2006 11:23 am

    I know, not a Lexus, but since it is the same issue, thought it could be of interest to others here.
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