In a way, I don't disagree. Up until a few years ago I always disabled my ABS pumpmotor during the summer months on the assumption that the probability of needing to stop quicker/quickly would overcome the much lower probability of loss of control due to wheel-lock.
I keep hoping that some bright engineer will soon realize that ABS need not be activated unless the VSC/PSM system indicates the need....
But...
Not all of "US" lived through that hundred years without ABS.
Personally I would redesign the DBW accelerator pedal system to use a torque motor instead of a return spring and then use the torque motor to increase the pedal resistance, and maybe some vibratory signaling, during times of automatic engine dethrottling.
Sorta of like many of the new electrically powered stearing assist systems are now doing, increasing resistance against a turning force that VSC indicates is undesireable.
One of the reasons I liked ABS even initially, that vibratory brake pedal was a "message".
Great idea. I called the 800-331-4331 number on 6-21-06 to document my tranny/navigator issues. My case number is 200606210210. Please....EVERYONE...call this number and let Toyota know there is an epidemic out here.
On another note....those of you who do not have the hesitation issue with their transmissions, consider yourselves extremely lucky, but kindly do not belittle our problems by suggesting this issue has been documented enough. It will have been documented enough when Toyota chooses to recognize there is a serious problem which needs fixing. I would love to rid myself of this problem by trading in my Avy for a Honda or whatever (anything but Toyota at this stage) but discovered that my Avy dropped from $35,000 to $25,000 in just a year. So much for Toyotas retaining their value.
Happy: First year depreciation is a KILLER!! If ya have the time and you're serious--try to sell to a private party. I just continue to use the manual mode for those occasions I know the tranny will do its "Murphy" impression! Bob
Thanks Oilcan and Bob for the suggestions of eBay or private party sale, but trade-in would be my only choice. I don't want anyone suing ME for the tranny issues.
If you live in the Seattle area and can readily demonstrate that your FWD or front torque biased AWD Toyota or Lexus exhibits the engine/transaxle delay/hesitation symptom I have a "trial" fix I would like to try.
My idea is to prevent the engine/transaxle ECU from commanding an upshift under some of the conditions defined within the Toyota TSB that "addresses" this issue.
By passively, non-destructively, monitoring the accelerator position sensor's output voltage we can determine that the accelerator pedal is in the process of being released and the instant it is released the trial circuit will activate the brake lighting system. Not the actual brakes, just the circuit that "tells" the ECU that the driver is braking and therefore perhaps provide an indication to the ECU that the driver clearly does not want to enter "cruise" mode.
Hopefully (it is a "trial") this will prevent the inadvertent/undesirable upshifts which as most of you know I believe are at the root cause of the delay/hesitation symptom.
The trial circuit will include a switch so the driver will have the ability to readily switch back and forth between the trial circuit and "as shipped".
Your theory sounds VERY logical. Sorry to say that I do not live in the Seattle area, but in Central Florida. Otherwise I would love to participate in your test. I am hoping you do get some volunteers and that your results find their way to this forum. Good luck.
You might want to do/try your own trial by simulating my circuit design.
Try using your left foot to apply the brakes just as you begin to lift the accelerator pedal to enter a coastdown mode. If my theory is correct that should do as well in preventing the ECU from commanding an upshift as would an actual circuit.
If it is somehow made clear to the ECU that you have no intention of entering "cruise" mode then it should not command an upshift.
...have tried driving a Toyota Matrix? I ask, because I'm driving a Pontiac Vibe, which is the same as the Matrix. It too has DBW. What it doesn't have is hesitation (they get the same programming, btw). Now, I would think that if Toyota can get the "low-end" Matrix right, surely they can get the Avalon right.
I would imagine the Matrix and Vibe both get outstanding FE even absent any "special" ASL firmware. Additionally the symptom only showed up recently on the I4 RAV4, presumably because the I4 crossed some HP/torque threshold.
I also doubt if the "little engine that could" in the Matrix/Vibe could generate any serious, unsafe, level of engine compression braking via the slushbox. Unless, that is, the driver is unwitting enough to downshift (presuming the firmware even allows that to happen during a coastdown) on a slippery roadbed.
No, I have not tried the Matrix....yet. Interesting to note that (assuming all Matrix's do not have hesitation) Toyota seems to put more effort into their non-flagship cars. The navigator in the Prius utilizes the preferred touch screen whereas the navigator in the Avalon is the archaic and totally useless joy stick variety. Go figure!
Well, I do notice that it is downshifting during heavy braking, but nothing dangerous.
(presuming the firmware even allows that to happen during a coastdown)
Oh yes, it allows it. :shades:
I do understand what you guys are talking about though. Several years ago my parents had a 2003 Silverado. It experienced the same symptom of not accelerating when floored. Plus when I was driving it, I went to pass someone, floored it and got almost no power. At the time (don't know about now) Chevy said that it was affecting all their trucks and that the Tahoe was the one they were experimenting on trying to fix it. They had to have gotten it fixed, since I drove a Trailblazer not that long ago that didn't have that problem.
Maybe we're somehow misunderstanding each other, how do you know your car is downshifting? Do you "feel" downshifting, sudden change in the rate of slowing, slowing FASTER, during "heavy" braking?
But be that as it may, that wasn't really the issue I was addressing/questioning.
Can you lift the throttle but stay off the brake and downshift, provide yourself with engine compression braking, using the paddle "steptronic" shift technique or by simply moving the shift lever into a lower notch. Furthermore at what speeds and into which gears?
Since it has become pretty clear that the vehicles exhibiting the delay/hesitation are upshifting during throttle closed coastdowns. I wonder if that can be defeated, easily, by manually commanding a downshift in a "timely" manner?
Using the paddle shifter, does the vehicle actually downshift, does it upshift anyway, or does it (best of all) simply remain in the current gear ratio?
If one of the "features" of this "new" engine/transaxle ECU control firmware is to prevent loss of directional control due to engine compression braking then I would think the firmware would exhibit reluctance, in the extreme, to actually downshift in the above conditions.
For instance I am quite certain sure that the transaxle in my 2001 AWD RX300 actually UPSHIFTS below about 10 MPH as I coast down for stopping, brakes applied or no. I can't be sure it doesn't even shift into neutral at that time. The feeling one gets is as if being bumped lightly from behind, or as if the braking suddenly became less powerful.
I am also quite sure/certain that it upshifts at about 30-45 MPH during throttle closed coastdown periods, the "slingshot effect" feeling. That last one is even verified within the Lexus RX300 shop/repair manuals.
I have an 06 Limited and rather than get frustrated witht he "quirky" tranny--I use the "manual" mode at those times I know the trnny will do its "Murphy" impression. Specifically, slowing down at yield signs, merging onto the Interstate, driving slow in parking lots----NO PROBLEMS when I use the "manual" mode. Guess its good thing I learned to drive a "stick shift" car 50+ years ago. I really wanted an automatic that was automatic. Toyota has a problem with the Avalon tranny--I've learned how to "control" the tranny. My biggest fear is that soome unsuspecting person is going to experiece the "quirky" tranny at an inopportune time--like merging into traffic and have an accident. Bob
RE: The feeling one gets is as if being bumped lightly from behind, or as if the braking suddenly became less powerful.
My theory on that "feeling" (which I also get when slowing down whether with brakes or without) is that the computer has sensed the need to downshift to the next lower gear and it is dictating what RPM it will jump to at the moment the downshift occurs. I believe the RPM they have programmed in, is higher than it should be, thus creating the sensation of being nudged from behind. Perhaps it was designed for a gear ratio that was originally intended, but changed AFTER writing the software.
My 2001 RX300 has a DIRECT mechanical connection twix the accelerator pedal and the throttle butterfly valve.
So I think not.
And I'm pretty sure mine doesn't actually downshift into 1st gear until I have come to a full stop, or in the alternative, "get on it" before coming to a full stop.
Which is why, I suspect, that these early non-DBW RXes with ASL firmware are having premature transaxle failures. My ATF HAD to be changed out (dirty looking brownish and smelled, odor, of burned resistors) out at 40,000 miles. Never had to do that with ANY Ford product, or previous Lexiis, even at over 100k miles.
Maybe we're somehow misunderstanding each other, how do you know your car is downshifting? Do you "feel" downshifting, sudden change in the rate of slowing, slowing FASTER, during "heavy" braking?
Yes, and at the same time I feel that, the RPMs come up about 500 or so.
Can you lift the throttle but stay off the brake and downshift, provide yourself with engine compression braking, using the paddle "steptronic" shift technique or by simply moving the shift lever into a lower notch. Furthermore at what speeds and into which gears?
Yes, I can lift the throttle (if it wasn't in the highest gear it possibly could be it will upshift) and then move the lever down. For example: At 70 MPH, I can press the OD button and it will execute a 4-3 downshift. If I then push it down to second, it will execute a 3-2 downshift. If I then push it down to 1st, it will execute a 2-1 downshift, after my speed has come down sufficiently. Does that answer your question?
For instance I am quite certain sure that the transaxle in my 2001 AWD RX300 actually UPSHIFTS below about 10 MPH as I coast down for stopping, brakes applied or no. I can't be sure it doesn't even shift into neutral at that time. The feeling one gets is as if being bumped lightly from behind, or as if the braking suddenly became less powerful.
Ouch, this is definitely strange design. Mine does not do this and downshifts as it should during deceleration. I cannot imagine any good reason for it upshifting under deceleration. However, I have experienced this feeling before in the 2004 Malibu I owned prior to the Vibe. It too had DBW. It worked perfectly well until they applied a PCM update to correct the transmission not upshifting at higher speeds (you had to practially lift off the throttle to get the 3-4 upshfit to occur). After they applied the update, every time I slowed down from highway speeds, right at 55 MPH, it felt like I was being bumped from behind. Since, near as I could tell, it hadn't downshifted before that, it was dropping out into neutral momentarily. I definitely had to apply more brake at that point.
The relevancy is that these are all other products made by Toyota. If Toyota makes other products (especially multiple other products) that work correctly, then they can't hide behind "that's how it is" as a defense. So it is useful for us to compare how other Toyota products work to determine if the Avalon is exhibiting normal Toyota behavior.
I understand what you are saying. But we are on an Avalon board, talking about the specific issues with the Avalon transmission. We need to keep that in mind and not go too far afield into other vehicles.
I have been driving my Av for 6mo. and the car is growing on me in a positive way. The Tranny is pretty much tamed by my feel for the car these days and the "intelligent systems". The NAV is working for me now that I know the quirks. My friends 07GS450H is nice 63K nice, but my car had similar systems to his and he lacked Laser or Radar cruise. I had a much larger trunk. I paid 1/2 of his purchase....I am thus far pretty satisfied.
Federal regulators propose rule that will require new safety feature on all U.S. passenger vehicles. By Peter Valdes-Dapena, CNNMoney.com staff writer POSTED: 12:01 p.m. EDT, September 14, 2006
NEW YORK (CNNMoney.com) -- The National Highway Traffic Safety Administration announced a proposed rule Thursday that will require Electronic Stability Control on all passenger vehicles in the United States.
Electronic Stability Control (ESC) uses a variety of sensors to detect when a car is a skid or rollover is happening, or is about to happen, because of hard cornering or slippery road conditions.
The system will rapidly apply the brakes for fractions of a second at individual wheels and simultaneously reduce engine speed to keep the vehicle under control. Such systems can often react even before the driver is aware that there is a problem.
The proposed rule would require all manufacturers to equip passenger vehicles under 10,000 pounds with ESC starting with the 2009 model year and to have the feature available as standard equipment on all vehicles by the 2012 model year.
Several studies have shown ESC to be extremely effective in preventing the most dangerous types of crashes.
About 43,000 people are killed in auto crashes in the United States each year. The agency estimates that ESC will save between 5,300 and 10,300 lives annually and prevent between 168,000 and 252,000 injuries.
NHTSA Administrator Nicole Nason called electronic stability control for cars "the greatest life saving improvement since the safety belt."
ESC tends to prevent more single-vehicle crashes, which usually involve a vehicle running off the road, the study found, but it also helps prevent the most serious, high-speed multi-vehicle crashes. The technology had little effect on less serious "fender bender" crashes, presumably because those types of crashes usually do not involve loss of vehicle control.
ESC is currently standard on about 40 percent of 2006 passenger vehicle models and is offered as an option on another 15 percent. On some vehicles, it is only available as part of a more expensive option package.
Adding ESC to vehicles that already have anti-lock brakes will cost car companies about $111 per vehicle, the agency estimates.
Ford Motor Co. recently announced that ESC would be standard on all of its cars and trucks by 2009.
General Motors has also said that it will make ESC standard on all of its vehicles by the end of the decade.
DaimlerChrysler's U.S. Chrysler Group has said it will have the technology as standard equipment on all of its SUVs, including Chrysler Jeep and Dodge vehicles, by the end of 2006.
Unlike other technologies, such as airbags and anti-lock brakes, car companies have a variety of different names for ESC. For example, General Motors calls their system StabiliTrak on SUVs and trucks and Active Handling on its cars. Chrysler calls their system Electronic Stability Program (ESP). Ford calls its ESC system AdvanceTrac.
NHTSA will be taking comments from the industry and the public about the proposed rule for the next 60 days.
yep, and there will not likely be much resistance - who in their right mind is going to argue with what is perceived to be a 'safety' feature. The article doesn't say, and I would imagine that it has not been decided yet - IMO these systems should be required to be user switchable, either on/off or for levels of intervention. Otherwise we will really be at the mercy of what some computer programmer (or lawyer) thinks is safe!
a friend with a 06 Subaru Forester, AWD, 170 hp 4 banger, 4 speed - been having some problems with the same sort of hesitation that Avalons can have - took the car in for service this AM. Per the service mgr., 'oh, they all do it, it is these new electronic transmissions' but 'we can reset the computer (referencing a Subaru TSB) which will help minimize the problem until the computer relearns' SOUND FAMILIAR? And the new Camry 5 and 6 speeds the same sort of complaints. Would also imagine in the 4 cylinder cars these behaviors are even more bothersome simply because there is less power available after the tranny does decide to engage. The point being that the Toyota trannies are working exactly like they are designed to - at the expense of some drivability - and in exchange for better FE, emissions, and possibly limiting torque steer issues in the higher power applications. Isn't technology wonderful?
I am thinking about getting a new or 06 car. The cars I've been considering are: Avalon, Acura TL, Lexus ES (I think too expensive for me) and Subaru Outback as a fallback.
I keep reading about the transmission problems. Are these issues across the board in all Toyota cars? i.e. Avalons and Lexus?
I assume there isn't and won't be a fix for the problem.
I have an 07 Avalon XLS and I have to tell you I havent expereinced any transmission issues so far... I will tell you that going from a 4 speed automatic to a 5 speed automatic does feel different and it does take alittle getting used to.. almost has a feel like it's geared lower. may be a bad way of describing it, but hopefully you understand what I mean... I've only had my avy for alittle more than 2 months, first japanese car I've ever owned, and so far, maybe the best car I've ever owned.
It begins to appear that these transmission's (transaxle, actually) throttle lag, 1-2 second engine/transaxle downshift delay/hesitation symptom/problems are across the board, insofar as FWD or front biased AWD vehicles are concerned.
There are posted complaints on this matter concerning VW, Ford, Toyota and Lexus FWD models.
I have come to quite firmly believe it is a result of an industry wide understanding of the hazards unique to FWD and they have now set out to somehow alleviate or eliminate those hazards.
I have a marvelous 2003 Avalon, but could not tolerate the transmission (hesitation) and acceleration (fly by wire) problems on the 2005. Have these been corrected yet?
I had an '03 before my '06 and can tell you except for the occasional "hunt" for the right gear (downhill around 35 - 45 mph) the '06 has no more delay (hesitation) in downshifting than my '03. It is an awesome powertrain, quick, smooth and no torque steer. I drove 3 different Avalons during my buying process and they all acted the same.
On the driver's side floor I have a rubber mat. Under the mat I have a wood block about 1 1/" thick. The block raises my foot high enough such that I have almost no tranny shift troubles.
Here is my complaint to the Toyota dealer here in Dubai:
"The overwhelming problem with this vehicle is the transmission; this was the source of my very first problem on the very first day of ownership. This car is consistently plagued by throttle lag/hesitation and the transmission is unable to provide a reliable ‘luxury car’ automatic gear changing solution, especially when in stop/start or in low speed traffic.
The automatic transmission will more often than not make the wrong choice for the car speed and road conditions and will result in unnecessary revving of the engine, jolting the car forward or doing nothing at all. When light pressure is applied to the accelerator pedal in an attempt smoothly accelerate, it is impossible to predict what will happen, making it very difficult to drive smoothly and tiresome to have to be constantly ‘on your guard’ to compensate.
It is literally anyone’s guess which one of the below options it may take. It may not react at all . no increase in the revs or drive to the wheels and do nothing for a few seconds just as if I was not even pushing on the pedal.
The below are all possible and this is after putting up with the throttle lag/hesitation period;
§ It may allow the engine to rev up to 2,500rpm and with no drive going to the wheels, (even when the road speed is already high enough to allow a change), hold this moment in ‘limbo’ and then slowly change the gear. § It may hold a shorter period of revving in ‘limbo’ and suddenly bump the gear in, causing a jolt of forward movement in the vehicle. § It may take the ‘huge thud’ option and try to break itself (and the driver). (has only happened twice) § It may accelerate normally (but only after the throttle lag/hesitation period.)
The problem is most noticeable in stop/start and low speed traffic but the transmission will often let the engine rev unnecessarily when accelerating while travelling at an already reasonable speed (60-80kmph). A point at which the car’s momentum should be more than sufficient to use the torque of the engine and not need to use the revs."
and the reply:
"Whilst the gear shift pattern does not suit your personal preferences, the performance across the full and varied condition range tested was to standard"
This car is a real pain in the Ar**... this is onyl one of several problems with the car..
doobre: I also have experienced the "quirky" transmission issue. Mine happened more as I slowed down and then tried to speed up after a Yield or doing a "rolling" stop. I solved the problem this way--while slowing down, i manually shift to 1st gear, speed up and then shift directly to drive--works everytime w/o any hesitation. Sad state of affairs to have to "shift" the transmission on an almost $40K car. Other than the "quirky" trans--this is the finest car I've ever owned. I get 30+ MPG at 75 MPH and over 26 MPG just running around here in the Missouri Ozarks. Hopee this procedure will work for you. Bob
If you browse about your will find owner complaints of throttle lag or engine delay/hesitation for Ford, VW, Toyota, Lexus and others, all concerning vehicles with automatic transmissions and mostly FWD or front biased AWD vehicles.
It is my firm belief that sometime in the mid to late ninties someone, or some group, with TONS of clout over the automtive industry issued an edict that the safety of FWD and front torque biased AWD had to be brought into line with their RWD and rear torque biased AWD brotheren.
My vote goes to the automotive insurance industry. Accident statistics most readily available, certainly with the CLOUT and enough synergy with the industry to want to keep this on the QT.
The safety issue involved the potential for loss of directional control due to engine braking, especially FRONT engine braking, in wintertime adverse roadbed conditions. There is also the issue of the potential for engine braking to interfere with ABS, again especially detrimental for FWD vehicles.
So, late in the last century the shift pattern/schedule was revised across the industry to address the safety issue. The new shift pattern dictated that anytime there was a FULL lift-throttle action by the driver the transaxle would be quickly upshifted so as to prevent any significant level of engine braking.
The problem that quickly arose from this change was that if the driver quickly returned to acceleration "mode" the engine was now at idle and the just previously commended upshift would deplete the ATF pressure/flow reserve. With little or no ATF pressure/flow available the subsequent downshift due to the driver's re-application of pressure to the gas pedal could not be quickly completed.
As evidence of Lexus has now replaced a LOT of early RX300 transaxles.
By 2001 Lexus had figured out the problem and increased the displacement of the ATF oil pump, gear type oil pump, to provide more pressure/flow at engine idle.
So, the 2001 RX300's, even with all equipped with the extra ATF cooling via the tow package, OVERHEATS the ATF to the point that the recommended traansaxle ATF service interval has declined from infinity (the life of the vehicle actually) to every 15,000 miles.
What to do, what to do...??
Oh, I know, let's use DBW, e-throttle, to delay the onset of engine torque until the subsequent downshift can be completed, the clutches firmly seated.
So the RX330 used the old standard ATF gear pump displacement but was equipped with DBW "to protect the drive train".
Regretably some one else in engineering had already decided that the VC, Viscous Clutch, in the AWD version was contributing to the overheating of the ATF and so it was removed, not to return until the advent of the RX350.
Is Lexus listening, do you suppose?
The final FIX...
SNOW mode...Assuming the new shift pattern upshift technique is to help alleviate accidents due to loss of directional control arising for engine braking, why not just have a SNOW mode that can be activated by the driver, by a rain sensor, or if the OAT hovers around or below freezing?
Upon a full lift-throttle event in SNOW mode the transaxle would remain in the same gear ratio (ready to SURGE forward on command) but the engine RPM, via DBW, would not be allowed to fall enough to provide a significant level of engine braking to the driven wheels, FRONT, rear, or ALL.
Absent being in SNOW mode the shift pattern could be the same as it was pre-2000, NO upshifting on full lift-throttle events.
No HIGH potential for engine braking, FRONT especially, to put your life at risk or interfere with ABS if the roadbed traction is satisfactory.
I guess on second thought ABS interference via engine braking might still be an issue. But that could addressed by keeping the upshift pattern but delaying it until the brakes are applied.
I recently purchased an '06 Limited w/12,000 miles on it. I've since driven it about 600 miles and was wondering if other Avalon owners have experienced what I seem to be regularly experiencing upon acceleration from either a dead stop or rolling stop. I'm experiencing a hesitation, or a "dead spot" in the forward movement of the vehicle when accelerating. If I methodically and "very gently" apply the accelerator the vehicle accelerates normally and smoothly. I don't consider myself a herky jerky applier of the foot feed and feel something's not quite right here. I'll obviously take it in under warranty for a "look see" but was wondering if anyone has experienced anything similar. Thank you
I've experienced the same thing and have even asked the dealer about it. They said that since the Avalons don't have an accelerator cable, but rather a completely electronic accelerator, that it might do exactly what you indicate. It's annoying as anything to have it do that.
You might want to inquire at your dealer just to see what they tell you.
Thanks for the response. I made an appointment with the local dealer to look at this and a couple other minor issues on Wednesday. I also read WWest's litany on transmission related issues associated with throttle response and hesitation. While interesting, I'm afraid he's coming from a technical side above my understanding level. I guess I'll just let the Toyota Service folks tell me "that's normal", there's nothing wrong with it, and learn a little different method of throttle control. Thanks again.
The transmission issue has been a subject of debate in the Avalon forums for many years. Numerous posts indicate a severe hesitation problem as the 5 speed changes the bottom 3 gears. It also has some auto-downshift traits in gear 5 (down to 4) that are at best annoying. The good news is that not all Avys appears to have the hesitation shift problems, just a few. My '07 Limited does not, at least not yet, @ 1k miles.
Driving with a "smooth foot" will lessen the hesitation chances considerably. Try to feel how the transmission acts and adjust. Some have posted that driving in S5 will also help but I have not tried it as the car is fine in D. Experiment with yours, post the results....
Having owned each generation of Avalon I would gladly trade the current 5 speed for the 4 speed of yesterday. The gas mileage and acceleration difference is not worth it and the constant hunt for a gear is noticable. But, we must move forward. You will probably be told your transmission is fine and it probably is. Keep the board informed.........
Glad to hear that others are experiencing the "hesitation" that some Forum reader's think is all in our minds!! Here's what I do--before coming to a Stop or Yield Sign, I slide the gear shift over to "manual" and put the tranny in 1st gear. Once I get rolling agian--NEVER with any hesitation--I slide the gear shift back to the "auto" mode---works EVERY TIME w/o fail. Tried one procedure to just leave it in "manual" and not downshift--just leave it in manual 5th--had the same hesitation issue. I'll keep using my procedure. Hope this helps! Bob
user777--I know this much--I certainly feel more confident and safer knowing that if I need to accelerate, it will go w/o hesitation. I also use the same procedure when merging with freeway traffic and again--NEVER a hesitation problem. I just DO NOT trust the transmission to operate properly. I read one Forum, about 6-8 month's ago, where a guy thought he was a "goner" because of hesitation when trying to merge. As long as it works--I'll keep using it. My 06 Limited is on Ebay 4 Sale--you can bet I'll be much more selective with the next car. Love the Avy except for the "quirky" tranny. I didn't spend almost $40K on a car with an automatic transmission to turn around and "manually" shift it to make it work properly. Bob
I rather doubt, seriously doubt, if manually downshifting the transaxle only to advoid downshift hesitation, and at accoringly reasonable roadspeeds (meaning NOT relying on the control ECU shift limiting to protect the transaxle) will result in an unusual wear level or early failure of the transaxle.
As a matter of fact many of the new Toyota owners manuals advise that engine compression braking can only be obtained via manually downshifting and with cruise control off(??).
Just keep in mind not to use this "downshift" procedure unless you are certain of good roadbed traction.
I'm glad to read that there are others having the same problem with the transmission; on the other hand, sad that Toyota has not done something about it. One mechanic advised me that all it would take was a software change, such as had been done on the Camry. I like my '06, but have had way too many problems for this price and quality of a car; so I'm in process of looking again to trade.
Ok I've read through a lot of post here and it seems that anyone with a problem has 2005 or 2006. Are there any problems with the 2007's or have they gotten it under control a bit. I did check in Consumer Reports and they rate the transmission as good. for 2006. Any input?
Well they have discontinued making the car, so I think that gives you the answer.. "it's a lemon stay away" that's my advise to anyone who asks my opinion. and since they have stopped making it, I take that as an admission by Toyota that there are unfixible issues..
I drive most of the time with 'S5' selected, which does reduce the lag and unnecessary revving quite a bit... but it still does not behave like it should and
I have many other little nagging issues which Toyota here (Dubai) say are intermittent and therefore not a real problem..
I recently test drove an 07 Touring and didn't find any issues with the car. I explicitly drove the car in a way that would induce hesitation but the tranny never got bogged down. Acceleration from 60 to 90 mph is fantastic. Didn't drive any 05 or 06 Avalon so I cant tell you about the problems.
I have had four acceleration surges with my 2005 toyota avalon xls,the most recent a near rear end collision. My contact with toyota has had polite discussion without admitting a problem exists or correction of the problem. A real shame that toyota is willing to sell cars that are touted as the finest,but are not willing toback up that claim when a buyer may be faced with a major safety issue.
Comments
I keep hoping that some bright engineer will soon realize that ABS need not be activated unless the VSC/PSM system indicates the need....
But...
Not all of "US" lived through that hundred years without ABS.
Personally I would redesign the DBW accelerator pedal system to use a torque motor instead of a return spring and then use the torque motor to increase the pedal resistance, and maybe some vibratory signaling, during times of automatic engine dethrottling.
Sorta of like many of the new electrically powered stearing assist systems are now doing, increasing resistance against a turning force that VSC indicates is undesireable.
One of the reasons I liked ABS even initially, that vibratory brake pedal was a "message".
On another note....those of you who do not have the hesitation issue with their transmissions, consider yourselves extremely lucky, but kindly do not belittle our problems by suggesting this issue has been documented enough. It will have been documented enough when Toyota chooses to recognize there is a serious problem which needs fixing. I would love to rid myself of this problem by trading in my Avy for a Honda or whatever (anything but Toyota at this stage) but discovered that my Avy dropped from $35,000 to $25,000 in just a year. So much for Toyotas retaining their value.
Bob
are more than some dealers want,if you paid 35k you will take some kind of hit but not 10k.
My idea is to prevent the engine/transaxle ECU from commanding an upshift under some of the conditions defined within the Toyota TSB that "addresses" this issue.
By passively, non-destructively, monitoring the accelerator position sensor's output voltage we can determine that the accelerator pedal is in the process of being released and the instant it is released the trial circuit will activate the brake lighting system. Not the actual brakes, just the circuit that "tells" the ECU that the driver is braking and therefore perhaps provide an indication to the ECU that the driver clearly does not want to enter "cruise" mode.
Hopefully (it is a "trial") this will prevent the inadvertent/undesirable upshifts which as most of you know I believe are at the root cause of the delay/hesitation symptom.
The trial circuit will include a switch so the driver will have the ability to readily switch back and forth between the trial circuit and "as shipped".
Try using your left foot to apply the brakes just as you begin to lift the accelerator pedal to enter a coastdown mode. If my theory is correct that should do as well in preventing the ECU from commanding an upshift as would an actual circuit.
If it is somehow made clear to the ECU that you have no intention of entering "cruise" mode then it should not command an upshift.
I also doubt if the "little engine that could" in the Matrix/Vibe could generate any serious, unsafe, level of engine compression braking via the slushbox. Unless, that is, the driver is unwitting enough to downshift (presuming the firmware even allows that to happen during a coastdown) on a slippery roadbed.
(presuming the firmware even allows that to happen during a coastdown)
Oh yes, it allows it. :shades:
I do understand what you guys are talking about though. Several years ago my parents had a 2003 Silverado. It experienced the same symptom of not accelerating when floored. Plus when I was driving it, I went to pass someone, floored it and got almost no power. At the time (don't know about now) Chevy said that it was affecting all their trucks and that the Tahoe was the one they were experimenting on trying to fix it. They had to have gotten it fixed, since I drove a Trailblazer not that long ago that didn't have that problem.
But be that as it may, that wasn't really the issue I was addressing/questioning.
Can you lift the throttle but stay off the brake and downshift, provide yourself with engine compression braking, using the paddle "steptronic" shift technique or by simply moving the shift lever into a lower notch. Furthermore at what speeds and into which gears?
Since it has become pretty clear that the vehicles exhibiting the delay/hesitation are upshifting during throttle closed coastdowns. I wonder if that can be defeated, easily, by manually commanding a downshift in a "timely" manner?
Using the paddle shifter, does the vehicle actually downshift, does it upshift anyway, or does it (best of all) simply remain in the current gear ratio?
If one of the "features" of this "new" engine/transaxle ECU control firmware is to prevent loss of directional control due to engine compression braking then I would think the firmware would exhibit reluctance, in the extreme, to actually downshift in the above conditions.
For instance I am quite certain sure that the transaxle in my 2001 AWD RX300 actually UPSHIFTS below about 10 MPH as I coast down for stopping, brakes applied or no. I can't be sure it doesn't even shift into neutral at that time. The feeling one gets is as if being bumped lightly from behind, or as if the braking suddenly became less powerful.
I am also quite sure/certain that it upshifts at about 30-45 MPH during throttle closed coastdown periods, the "slingshot effect" feeling. That last one is even verified within the Lexus RX300 shop/repair manuals.
Bob
My theory on that "feeling" (which I also get when slowing down whether with brakes or without) is that the computer has sensed the need to downshift to the next lower gear and it is dictating what RPM it will jump to at the moment the downshift occurs. I believe the RPM they have programmed in, is higher than it should be, thus creating the sensation of being nudged from behind. Perhaps it was designed for a gear ratio that was originally intended, but changed AFTER writing the software.
So I think not.
And I'm pretty sure mine doesn't actually downshift into 1st gear until I have come to a full stop, or in the alternative, "get on it" before coming to a full stop.
Which is why, I suspect, that these early non-DBW RXes with ASL firmware are having premature transaxle failures. My ATF HAD to be changed out (dirty looking brownish and smelled, odor, of burned resistors) out at 40,000 miles. Never had to do that with ANY Ford product, or previous Lexiis, even at over 100k miles.
Yes, and at the same time I feel that, the RPMs come up about 500 or so.
Can you lift the throttle but stay off the brake and downshift, provide yourself with engine compression braking, using the paddle "steptronic" shift technique or by simply moving the shift lever into a lower notch. Furthermore at what speeds and into which gears?
Yes, I can lift the throttle (if it wasn't in the highest gear it possibly could be it will upshift) and then move the lever down. For example: At 70 MPH, I can press the OD button and it will execute a 4-3 downshift. If I then push it down to second, it will execute a 3-2 downshift. If I then push it down to 1st, it will execute a 2-1 downshift, after my speed has come down sufficiently. Does that answer your question?
For instance I am quite certain sure that the transaxle in my 2001 AWD RX300 actually UPSHIFTS below about 10 MPH as I coast down for stopping, brakes applied or no. I can't be sure it doesn't even shift into neutral at that time. The feeling one gets is as if being bumped lightly from behind, or as if the braking suddenly became less powerful.
Ouch, this is definitely strange design. Mine does not do this and downshifts as it should during deceleration. I cannot imagine any good reason for it upshifting under deceleration. However, I have experienced this feeling before in the 2004 Malibu I owned prior to the Vibe. It too had DBW. It worked perfectly well until they applied a PCM update to correct the transmission not upshifting at higher speeds (you had to practially lift off the throttle to get the 3-4 upshfit to occur). After they applied the update, every time I slowed down from highway speeds, right at 55 MPH, it felt like I was being bumped from behind. Since, near as I could tell, it hadn't downshifted before that, it was dropping out into neutral momentarily. I definitely had to apply more brake at that point.
The relevancy is that these are all other products made by Toyota. If Toyota makes other products (especially multiple other products) that work correctly, then they can't hide behind "that's how it is" as a defense. So it is useful for us to compare how other Toyota products work to determine if the Avalon is exhibiting normal Toyota behavior.
Thanks!
Federal regulators propose rule that will require new safety feature on all U.S. passenger vehicles.
By Peter Valdes-Dapena, CNNMoney.com staff writer
POSTED: 12:01 p.m. EDT, September 14, 2006
NEW YORK (CNNMoney.com) -- The National Highway Traffic Safety Administration announced a proposed rule Thursday that will require Electronic Stability Control on all passenger vehicles in the United States.
Electronic Stability Control (ESC) uses a variety of sensors to detect when a car is a skid or rollover is happening, or is about to happen, because of hard cornering or slippery road conditions.
The system will rapidly apply the brakes for fractions of a second at individual wheels and simultaneously reduce engine speed to keep the vehicle under control. Such systems can often react even before the driver is aware that there is a problem.
The proposed rule would require all manufacturers to equip passenger vehicles under 10,000 pounds with ESC starting with the 2009 model year and to have the feature available as standard equipment on all vehicles by the 2012 model year.
Several studies have shown ESC to be extremely effective in preventing the most dangerous types of crashes.
About 43,000 people are killed in auto crashes in the United States each year. The agency estimates that ESC will save between 5,300 and 10,300 lives annually and prevent between 168,000 and 252,000 injuries.
NHTSA Administrator Nicole Nason called electronic stability control for cars "the greatest life saving improvement since the safety belt."
ESC tends to prevent more single-vehicle crashes, which usually involve a vehicle running off the road, the study found, but it also helps prevent the most serious, high-speed multi-vehicle crashes. The technology had little effect on less serious "fender bender" crashes, presumably because those types of crashes usually do not involve loss of vehicle control.
ESC is currently standard on about 40 percent of 2006 passenger vehicle models and is offered as an option on another 15 percent. On some vehicles, it is only available as part of a more expensive option package.
Adding ESC to vehicles that already have anti-lock brakes will cost car companies about $111 per vehicle, the agency estimates.
Ford Motor Co. recently announced that ESC would be standard on all of its cars and trucks by 2009.
General Motors has also said that it will make ESC standard on all of its vehicles by the end of the decade.
DaimlerChrysler's U.S. Chrysler Group has said it will have the technology as standard equipment on all of its SUVs, including Chrysler Jeep and Dodge vehicles, by the end of 2006.
Unlike other technologies, such as airbags and anti-lock brakes, car companies have a variety of different names for ESC. For example, General Motors calls their system StabiliTrak on SUVs and trucks and Active Handling on its cars. Chrysler calls their system Electronic Stability Program (ESP). Ford calls its ESC system AdvanceTrac.
NHTSA will be taking comments from the industry and the public about the proposed rule for the next 60 days.
The article doesn't say, and I would imagine that it has not been decided yet - IMO these systems should be required to be user switchable, either on/off or for levels of intervention. Otherwise we will really be at the mercy of what some computer programmer (or lawyer) thinks is safe!
And the new Camry 5 and 6 speeds the same sort of complaints. Would also imagine in the 4 cylinder cars these behaviors are even more bothersome simply because there is less power available after the tranny does decide to engage.
The point being that the Toyota trannies are working exactly like they are designed to - at the expense of some drivability - and in exchange for better FE, emissions, and possibly limiting torque steer issues in the higher power applications. Isn't technology wonderful?
I keep reading about the transmission problems. Are these issues across the board in all Toyota cars? i.e. Avalons and Lexus?
I assume there isn't and won't be a fix for the problem.
Roland
There are posted complaints on this matter concerning VW, Ford, Toyota and Lexus FWD models.
I have come to quite firmly believe it is a result of an industry wide understanding of the hazards unique to FWD and they have now set out to somehow alleviate or eliminate those hazards.
2025 Ram 1500 Laramie 4x4 / 2023 Mercedes EQE 350 4Matic / 2022 Icon I6L Golf Cart
"The overwhelming problem with this vehicle is the transmission; this was the source of my very first problem on the very first day of ownership. This car is consistently plagued by throttle lag/hesitation and the transmission is unable to provide a reliable ‘luxury car’ automatic gear changing solution, especially when in stop/start or in low speed traffic.
The automatic transmission will more often than not make the wrong choice for the car speed and road conditions and will result in unnecessary revving of the engine, jolting the car forward or doing nothing at all. When light pressure is applied to the accelerator pedal in an attempt smoothly accelerate, it is impossible to predict what will happen, making it very difficult to drive smoothly and tiresome to have to be constantly ‘on your guard’ to compensate.
It is literally anyone’s guess which one of the below options it may take. It may not react at all . no increase in the revs or drive to the wheels and do nothing for a few seconds just as if I was not even pushing on the pedal.
The below are all possible and this is after putting up with the throttle lag/hesitation period;
§ It may allow the engine to rev up to 2,500rpm and with no drive going to the wheels, (even when the road speed is already high enough to allow a change), hold this moment in ‘limbo’ and then slowly change the gear.
§ It may hold a shorter period of revving in ‘limbo’ and suddenly bump the gear in, causing a jolt of forward movement in the vehicle.
§ It may take the ‘huge thud’ option and try to break itself (and the driver). (has only happened twice)
§ It may accelerate normally (but only after the throttle lag/hesitation period.)
The problem is most noticeable in stop/start and low speed traffic but the transmission will often let the engine rev unnecessarily when accelerating while travelling at an already reasonable speed (60-80kmph). A point at which the car’s momentum should be more than sufficient to use the torque of the engine and not need to use the revs."
and the reply:
"Whilst the gear shift pattern does not suit your personal preferences, the performance across the full and varied condition range tested was to standard"
This car is a real pain in the Ar**... this is onyl one of several problems with the car..
Definitely NOT recommended..
Bob
It is my firm belief that sometime in the mid to late ninties someone, or some group, with TONS of clout over the automtive industry issued an edict that the safety of FWD and front torque biased AWD had to be brought into line with their RWD and rear torque biased AWD brotheren.
My vote goes to the automotive insurance industry. Accident statistics most readily available, certainly with the CLOUT and enough synergy with the industry to want to keep this on the QT.
The safety issue involved the potential for loss of directional control due to engine braking, especially FRONT engine braking, in wintertime adverse roadbed conditions. There is also the issue of the potential for engine braking to interfere with ABS, again especially detrimental for FWD vehicles.
So, late in the last century the shift pattern/schedule was revised across the industry to address the safety issue. The new shift pattern dictated that anytime there was a FULL lift-throttle action by the driver the transaxle would be quickly upshifted so as to prevent any significant level of engine braking.
The problem that quickly arose from this change was that if the driver quickly returned to acceleration "mode" the engine was now at idle and the just previously commended upshift would deplete the ATF pressure/flow reserve. With little or no ATF pressure/flow available the subsequent downshift due to the driver's re-application of pressure to the gas pedal could not be quickly completed.
As evidence of Lexus has now replaced a LOT of early RX300 transaxles.
By 2001 Lexus had figured out the problem and increased the displacement of the ATF oil pump, gear type oil pump, to provide more pressure/flow at engine idle.
So, the 2001 RX300's, even with all equipped with the extra ATF cooling via the tow package, OVERHEATS the ATF to the point that the recommended traansaxle ATF service interval has declined from infinity (the life of the vehicle actually) to every 15,000 miles.
What to do, what to do...??
Oh, I know, let's use DBW, e-throttle, to delay the onset of engine torque until the subsequent downshift can be completed, the clutches firmly seated.
So the RX330 used the old standard ATF gear pump displacement but was equipped with DBW "to protect the drive train".
Regretably some one else in engineering had already decided that the VC, Viscous Clutch, in the AWD version was contributing to the overheating of the ATF and so it was removed, not to return until the advent of the RX350.
Is Lexus listening, do you suppose?
The final FIX...
SNOW mode...Assuming the new shift pattern upshift technique is to help alleviate accidents due to loss of directional control arising for engine braking, why not just have a SNOW mode that can be activated by the driver, by a rain sensor, or if the OAT hovers around or below freezing?
Upon a full lift-throttle event in SNOW mode the transaxle would remain in the same gear ratio (ready to SURGE forward on command) but the engine RPM, via DBW, would not be allowed to fall enough to provide a significant level of engine braking to the driven wheels, FRONT, rear, or ALL.
Absent being in SNOW mode the shift pattern could be the same as it was pre-2000, NO upshifting on full lift-throttle events.
No HIGH potential for engine braking, FRONT especially, to put your life at risk or interfere with ABS if the roadbed traction is satisfactory.
I guess on second thought ABS interference via engine braking might still be an issue. But that could addressed by keeping the upshift pattern but delaying it until the brakes are applied.
You might want to inquire at your dealer just to see what they tell you.
Thanks for the response. I made an appointment with the local dealer to look at this and a couple other minor issues on Wednesday. I also read WWest's litany on transmission related issues associated with throttle response and hesitation. While interesting, I'm afraid he's coming from a technical side above my understanding level. I guess I'll just let the Toyota Service folks tell me "that's normal", there's nothing wrong with it, and learn a little different method of throttle control. Thanks again.
Driving with a "smooth foot" will lessen the hesitation chances considerably. Try to feel how the transmission acts and adjust. Some have posted that driving in S5 will also help but I have not tried it as the car is fine in D. Experiment with yours, post the results....
Having owned each generation of Avalon I would gladly trade the current 5 speed for the 4 speed of yesterday. The gas mileage and acceleration difference is not worth it and the constant hunt for a gear is noticable. But, we must move forward. You will probably be told your transmission is fine and it probably is. Keep the board informed.........
Bob
i'm not sure all owners would feel confident doing the same.
As a matter of fact many of the new Toyota owners manuals advise that engine compression braking can only be obtained via manually downshifting and with cruise control off(??).
Just keep in mind not to use this "downshift" procedure unless you are certain of good roadbed traction.
Rich
I drive most of the time with 'S5' selected, which does reduce the lag and unnecessary revving quite a bit... but it still does not behave like it should and
I have many other little nagging issues which Toyota here (Dubai) say are intermittent and therefore not a real problem..
cheers
their "flagship" vehicle? not according to their website.
Source please?
2025 Ram 1500 Laramie 4x4 / 2023 Mercedes EQE 350 4Matic / 2022 Icon I6L Golf Cart
avalon xls,the most recent a near rear end collision.
My contact with toyota has had polite discussion without
admitting a problem exists or correction of the problem.
A real shame that toyota is willing to sell cars that are touted as the finest,but are not willing toback up that claim when a buyer may be faced with a major safety issue.