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2005-2007 Toyota Avalon

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Comments

  • easyrider300measyrider300m Posts: 1,116
    so I guess SIZE (of the foot) does matter....
  • regisregis Posts: 94
    "I have a rubber mat in the drivers floor that raises my foot just enough to hit the sweet spot on the gas pedal"

    Me too. That must be the reason why my small feet have not experienced the hesitation others have.
  • captain2captain2 Posts: 3,971
    see post 11847 - obviously agree with you, while everybody is seemingly consumed with this foot position stuff (which does make a difference), I think the real cause is the transmission's tendency to hold onto too high gears, a 'programming' issue based on Toyta's desire to wring out every possible mpg. I would bet that the upcoming switch to a 6 speed in the '07 might actually have more 'hesitation'
  • motownusamotownusa Posts: 836
    Unlikely, as the Camry with the 6 speed auto is already out. Haven't heard any complaints yet. Toyota said that the transmission downshift has been greatly improved over the 5 speed model and I believe it. I will find out soon as I personally am going to test drive an SE V6.
  • captain2captain2 Posts: 3,971
    maybe so and would be interested to know what you find. But, I have never seen anything mentioned about it in any of the multiple tests and reviews done on the Avalon over the last year, either. If we are to attribute the 'hestitation' to gear searching on multiple gear downshifts and we also accept that our transmissions are 'designed' to hold onto the highest gears possible (for economy?), then adding a gear would logically aggravate the 'problem'.
  • retired7retired7 Posts: 133
    Has anyone compared driving/hesitation in the "S" mode and using "sweet spot" on gas pedal vs driving in regular "D" mode using "sweet spot"?

    Like to hear from any of Toyota's or Suppliers design engrs out there who would know what were the design considerations/attributes used in the design of the Avy's gas pedal?

    NWBLIZZARD
  • retired7retired7 Posts: 133
    Watch out for termites!
  • captain2captain2 Posts: 3,971
    have certainly tried it - driving in 'S' seems to make 4th the default gear, so things do improve on reapplication of throttle a bit simply because, I guess, that the downshifts involve one less gear. Truly shifting manually does, of course, eliminate any gear searching but defeats the purpose of the auto. trans.
  • motownusamotownusa Posts: 836
    I think most modern 6 speed auto can downshift multiple gears at once. If you really hammer the throttle you could go down from 6th to 4th without going through 5th. At least that is how it works in the new IS with the 6 speed auto.
  • motownusamotownusa Posts: 836
    But I do agree with you about the transmission holding onto to the highest gear possible for the sake of fuel efficiency and emission ratings. I doubt Toyota will modify that aspect of the transmission behavior if it results in lower gas mileage and emission rating.
  • stlmostlmo Posts: 40
    Rarely get to drive the wife's 05 Avalon since she loves it so much but traded vehicles with her yesterday to try the pedal effect. Previously when I had driven it I had noticed it sometimes would rev up somewhat without a corresponding gain in acceleration (a lag). She says she has no complaints with its driveability. I found out yesterday when driving in my normal foot position the lag was still there and then changed the position so my heel was closer to the pedal and I had better contact with it. The result was the disappearance of the lag. I guess I am at least a semi-toe driver. The new position is not uncomfortable, just different. By the way my shoe size is 10 1/2 and I brake with my left foot. Great car so far; just turned 7,000 mi with no warranty work yet needed (they did realign 1 of the exhaust tips at its 1st oil change).
  • captain2captain2 Posts: 3,971
    didn't mean to imply that out trannies were necessarily going thru intermediary gears on the way down. Our 5 speeds are new to the 05 and are electronically controlled to boot - so I'm thinking that in that situation that you are coasting down at 30mph, the trans is still in 5th, and then, you hit the accelerator, the transmission will actually decide what gear is best for whatever IT decides is needed and then, attempting in some fashion to go directly to that gear. Maybe somebody out there with a better knowledge of how these things really work?
    Did do a little surfing, looking for some explanations and stumbled on a Volkswagen site espousing all the virtues of their new electronically controlled transmissions - which I found somewhat interesting - have read nothing but bad stuff about it as far as drivability is concerned.
  • I have an occasional hesitation in my Avalon, and it definitely can NOT be eliminated by changing the foot position on the pedal. The two circumstances when it generally occurs are:

    1. Braking with at least moderate pressure on the brake pedal and then lifting off the brake and quickly pressing the accelerator.

    2. Lifting completely off the throttle while accelerating and then immediately pressing the accelerator again.

    The hesitation is usually reduced or eliminated simply by waiting longer after lifting off the brake or accelerator before pressing the accelerator. Trying different foot positions on the accelerator had no effect. Therefore, it appears to me that the hesitation is due to the software that controls the transmission shifting rather than the foot position on the accelerator.

    Placing the shifter in "S" tends to reduce the frequency of the hesitation but does not completely eliminate it. I'm guessing that the difference is due to slightly different software programming for the manual shift mode.
  • alan_salan_s Posts: 356
    06avalonxl describes the hesitation problem accurately:

    1. Braking with at least moderate pressure on the brake pedal and then lifting off the brake and quickly pressing the accelerator.

    2. Lifting completely off the throttle while accelerating and then immediately pressing the accelerator again.

    In stop and go traffic this is done repeatedly, which sends the transmission into a fluster.

    There are multiple issues that are coming into play here. My observations are as follows, and I apologize for the length of the post but I believe I am on to something…

    I examined our new Honda Pilot's DBW implementation (which is faultless) and compared its characteristics and functionality with the Avalon.

    1. I discovered that in the Avalon there is a "dead spot" from accelerator idle-position to on-throttle, so an inherent time-delay exists every time the pedal is depressed when fully off.

    2. Upon further examination I observed that due to the curved design of the accelerator pedal, greater foot travel is required to reach the initial on-throttle position if the foot is placed lower on the pedal because of the leverage and the curvature of the pedal which causes the top of the foot to pivot downwards, as the gas pedal moves away which further compounds the problem.
    This results in greater foot travel if the foot is placed lower on the gas pedal and an increased time-interval before reaching the on-throttle trigger position, so the hesitation is longer. This explains the "foot position" voodoo phenomenon being described in this forum.

    3. When the accelerator is on-throttle and then the foot is removed, the accelerator returns to idle-position, and the transmission appears to shift into a higher gear irrespective of vehicle speed, and the engine RPM's drop.

    4. When the foot is reapplied to the accelerator after this deceleration, there is the initial dead-spot delay depending on your foot position, plus a further delay for the transmission to reselect an appropriate gear for the current vehicle/engine speed.

    5. To compound this, sometimes the transmission does not engage immediately so there is an RPM surge or "slip" until the transmission engages, on occasion with a bang, or on other occasions the transmission selects a gear and then immediately afterwards, selects an alternative gear.

    6. It appears that an off-throttle event is a trigger for the transmission computer to select the highest gear possible - perhaps for fuel economy or emission reasons.

    These sequences of events result in the hesitation and general transmission/drivability issues of concern.

    I also observed that if the foot is not completely removed from the accelerator, but lifted just enough to be just at idle, the transmission remains in the current gear, and
    a) when reapplying the throttle there is no hesitation because the initial dead-spot is not being traveled and
    b) the transmission “thinks” the foot is still on the accelerator and does not recompute it's gear selection.

    Taking all this into consideration, I tried an experiment to test my theory.

    I fabricated a piece of plastic of appropriate thickness that when installed in the correct position in the accelerator housing upwards of the pedal shaft, I slightly changed the "off-throttle" or home position of the gas pedal to be just below the point at where RPM's increase (just below off-idle), essentially taking up the initial dead-spot or slack, and simulating a partly on-throttle condition to be signalled to the computer, without raising the idle RPM's.

    I have been driving the Avalon like this for 4 days now and have found that the hesitation has all but disappeared. There is no hesitation "off the mark" - the engine responds immediately to on-throttle, and when lifting off the accelerator and reapplying during traffic, the transmission remains in the current gear because the ECU “thinks” the foot is still on throttle (or shifts DOWN if braking) and simply picks up when the throttle is reapplied. THERE IS NO GEAR HUNTING, NO MORE "SLIPPING" AND NO MORE HESITATION!

    I am not sure whether this “slack” is a design intent or whether the hall-effect throttle controllers have out of spec minimum voltages that is causing the problem in some vehicles and not others. Perhaps our friend wwest can shed further light on this.

    I am looking into making a permanent fix for this based on my findings, but I think Toyota need to redesign the throttle controller to eliminate the slack, and redesign the gas pedal.
  • algeealgee Posts: 78
    Thank you for the most excellent post. At last, an engineers view point and it points out that this is a design flaw.

    Lets add to or take this Edmunds complaining to Toyota and demand a fix, I have.
  • gerry100gerry100 Posts: 100
    Just the idea that people are modifying the gas pedals may alarm Toyota enough to generate a fix.

    Changing out to a redesigned part would be easy as this is basicaalky a plug in.( one of the major cost advantages of the DBW system).

    Of course a redesign part would require new tooling and developemnt and testing which will take some time.
  • alan_salan_s Posts: 356
    Actually the fix appears exceedingly cheap and simple and could be applied in a dealer-installed TSB.

    Toyota could design and manufacture a clip and "tongue" that slides and clips over the pedal shaft, with the tongue positioned upward into the controller housing so that the thickness of the tongue lowers the gas pedal into the corrected home position.

    Alternatively the plastic controller housing could be modified to accomodate an adjustment screw so that the pedal shaft rests on the screw when fully released, allowing the home position to be adjusted.

    Toyota, are you listening?

    Deafening silence, I am afraid.
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  • neil5neil5 Posts: 118
    I have heard that if you call or send registered letter to home base (1-800-XXXX) Toyota California. That you get pretty fast attention to problems. I love the car, but this issue should be addressed by toyota and offer a fix. I drove the IS 350 Lexus and I was impressed..but too small for the money
  • alan_salan_s Posts: 356
    After having no luck with a local Toyota dealer over the transmission/hesitation issues, I called Toyota HQ, opened a case and received a case reference number.
    Toyota referred me back to the local dealer who conceded that Toyota have received many complaints about the transmission but Toyota consider the transmission behavior as "characteristics" of the transmission, and not a defect. They promptly closed the case.
    Toyota have become too big and successful to care about silly nuisances like customers.
    Sounds like GM's arrogant attitude in the 1980's, and look at where they are now. It will take Toyota far less than 20 years to fall from grace, but it will happen...
    My crystal ball shows me the David that will unseat Goliath, and it is spelled H Y U N D A I.
  • bobwileybobwiley Posts: 241
    Thank goodness, (SO FAR), I haven't experienced the transmission shudder. sounds like if enough people got together (like here in the Forum), there must be a lawyer who could advise about a Class Action Suit. Paying near $30K and up to nearly $40K for a car, the transmission should shift smoothly. Also, the infamous gas pedal demon hasn't struck either----maybe its my 12W feet?
  • j_hbrockj_hbrock Posts: 32
    I would appreciate some advice on the Avalon. Specifically the Touring trim.

    (1) For safety reasons I figured adding the VSC/Brake assist would be worth it but would I "lose" out one some of the benefits the Touring trim offers?

    Obviously I do not want lose control of my car and the VSC can aid in that not happening (to a point). But, I wouldn't want it to "take over" just because I am taking an curve or cloverleaf onramp aggressively.

    I heard many times the Touring trim buyers opt NOT to get the VSC. Is that true? Do you lose some of the benefits on the Touring by having VSC?

    (2) Regarding the 2007. If you were me, and not in a rush, would YOU wait for the '07?

    Is a 6 speed tranny worth waiting for? Would I REALLY notice a difference? As far as I know the 6-speed is the only real difference right?

    Do you suspect the '07 to be a little more expensive than the '06? I am willing to hold off...save a little more for the down payment...IF the '07 will really be worth waiting for.

    What would you do?
  • bluesman3bluesman3 Posts: 202
    Safety is a big reason to get the VSC option, I too have read that stability control could be the difference between survival or death in an accident. Frankly the Avalon is a big car and it will never be a contender for the slalom course, so why drive it like that? What about ice on the road? (if you live in the cold belt). On the other hand we've managed to live this long without such technology. What we're buying here is F.U.D. (fear, uncertainty and doubt).

    I've driven the 6 speed in the new Camry and I understand that it is a much improved design over the 5 speed. The DBW system is still there but at least the hardware of the trans. has been improved. I did feel a small lag in response on the 6 speed, enough that you'd learn to anticipate it. DBW issue or tranny? Probably DBW..

    This is all speculation of course since we don't know for sure if they'll offer the 6 speed in the 07' Avalon. It's a good hunch though....
  • captain2captain2 Posts: 3,971
    own a 05 Av Touring now with 25K miles - no VSC - absolutely love the car and like the way it drives much more than the other trims. Still no sports car though.
    As far as VSC goes, my opinion is that it is something to be avoided if you can until Toyota wakes up and decides to put a 'disable' switch in. While it is certainly true that VSC can prevent you from getting the car 'too deep', it may also interfere with the car's evasive capabilities in emergency situations. TRAC, however, which I think comes with the VSC option, can also create problems on snowy/icy roads - the car can literally refuse to move! For the life of me, don't understand why folks insist on things like VSC and TRAC - guess if it is a 'safety feature' it must be good?
    Don't think the 6 speed should make much difference - if the 07 Camry is an indication, economy and acceleration about the same. The way the transmission works may be better or worse depending on how Toyota 'programs' it.
  • regarding #1, I just went to toyota.com and checked out Southeast Toyota's inventory.

    Out of the 102 Tourings in inventory, only 1 has the VSC option (less than 1 percent).

    Out of the 629 XLS in inventory, 136 have the VSC option (almost 22%).

    Out of the 893 Limiteds in inventory, 121 have the VSC option (13.5%).

    I think this sort of verifies what I told you on the other board....that people who want the tighter suspension (Touring) generally do not want the limitations that the VSC package may present.

    I love the Touring. I have had a few occasions to be fairly aggressive in moderate turns...and I have never felt like the car was getting away from me. as someone suggested, the Avalon (even in the Touring trim) is not a sports sedan. I could not take a sharp turn aggressively. If you believe you're going to drive a car in a manner that requires a VSC/TRAC system, you might want to consider other cars (where the VSC system can be shut off). If, however, you want something a lot more comfortable than a sports sedan...but just as powerful and with some agility...then get the Avalon Touring without VSC/TRAC. Notably, the tires on the Touring are made for a little more aggressive driving than the XLS. The Touring tires are rated A-A...so they are going to grip the road fairly well.
  • finfin atlantaPosts: 588
    Here are a few more thoughts:

    1. The way you ask the question on VSC tends to suggest you would not like the automated controls. And it appears it cannot be turned off. You are probably going to become frustrated when it kicks in. Better to spend money on other options.

    2. On the assumption that cars get better each model year as the manufacturer refines the product, wait on the '07 if you have the time. It may cost a few dollars more and have the 6 speed (maybe) but it should also have other minor things, like options, that make it just plain better. It will also be a year younger when traded (meaningful only if you trade in about 5 years or less, under 100k miles).

    Be glad you asked questions here, this is one of the best forums for information in all of Edmunds.com......... :)
  • captain2captain2 Posts: 3,971
    your lengthy post on this is wonderful, comments 3 and 6 re: holding onto higher gears and not downshifting certainly applies to the way my car drives. Would be interested to know if you have noticed any decrease in mpg after your fix and whether it continues to work effectively.
    It would seem logical that if this behavior is, indeed, related to the car's EPA/Emission ratings that Toyota would likely deny any problem, meaning that they are intentionally sacrificing some drivability for economy.
  • alan_salan_s Posts: 356
    Thanks, Captain.

    So far I haven't noticed any decrease in economy, it is actually up by 1 mpg (perhaps due to no more "slipping") but I need more time to make any assumptions on the effect on fuel consumption.

    As far as drivability is concerned - I am absolutely amazed and delighted at the result. For the first time I actually enjoy driving the car. It is responsive and the drivetrain feels "tight" and cohesive and the transmission is actually smooth and orderly. It seems to have adopted a completely different shift-pattern.

    There is obviously a problem induced by a sequence of on-throttle, off-throttle situations and it seems to be the off-throttle event that upsets things.

    It is beyond me why Toyota have not either changed the design of the throttle controller, or implemented a software change to accomodate this condition. Seems a no-brainer to me.
  • samchinchsamchinch Posts: 47
    You should post a picture of what you have done so that everyone can modify their avalons.
  • alan_salan_s Posts: 356
    I don't think it is a good idea for just anyone to mess with this. If it is done incorrectly the throttle could stick or not return to idle properly - obviously with possible dangerous results. I don't want to be responsible if someone unleashes all 268hp at once and launches their Avalon at a trajectory aimed at the garage wall!
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