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Toyota RAV4 Throttle Lag

steverstever Viva Las CrucesPosts: 41,010
This discussion is to figure out what to do if your RAV4 suffers from throttle lag.

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Comments

  • mikenew2mikenew2 Posts: 4
    I too have had my RAV4 for about 3 months, 2wd 4cyl sport. I have noticed the downshifting issue more and more. I had no complaints about acceleration when i first got the SUV, but it has become a noticible issue, so much so that passengers comment on the jerk when the transmission downshifts. In traffic, when I need to pass or change lanes, the tansmission clunk and throttle lag is almost dangerous. I have started feeling that I cannot live with a car that performs this way for long.

    On the other hand, I have not had any problem with braking.

    Another criticism is the build of the interior, which seems cheap and loose - lots of the plastic seams don't seem well fitted, the window switch plate came out of the door once while pulling up on the switch to close the window. My previous Toyotas seemed more solid.
  • bob777bob777 Posts: 19
    Hmmm
    Throttle lag is a good way to put it. I think it's dangerous and I thought I was going to get nailed both times it happened to me.

    The break issue seems to happen under emergency breaking situations. They work ok at first but then begin to fade. Hard breaking from say, at least 45 MPH.
  • mikenew2mikenew2 Posts: 4
    I have not had any particularly hard braking incidents, knock on wood, so I can't speak to it. But I will pay attention if it happens. Not looking forward to what my dealership will say about the transmission and throttle issue... :lemon: ???
  • bob777bob777 Posts: 19
    My dealer told me I needed to learn to drive a Toyota and learn how to avoid these situations. I'm taking it to another dealer, but I doubt they will admit anything until there is an accident and they have to by court order.

    The break issue happened early on. They have gotten better with additional miles and I would say they are satisfactory now. May have been an issue with new pads.
  • fsmmcsifsmmcsi Posts: 792
    Is this the same problem as people are having with the Avalons? I notice that both models have a 5-speed automatic transmission, while the Camry has a 6-speed unit.

    I have decided to rent one for an extended test drive, and have discovered that some Toyota dealers rent new models. Toyota's vehicle rental web site even promotes rentals for such extended test drives.
  • bob777bob777 Posts: 19
    I would not be surprised, but I don't know. Renting one is a great idea. I wish I would have thought of that.

    My brother in law has an 06 Avalon and he has no issues with it.
  • mterrellmterrell Posts: 21
    I bought the 2006 base 2wd and I have noticed a lag in exceleration and brake fade. Seems that its got better now that it has about 1600 miles on it. So maybe it a break in thing with this suv . The lag could be a problem though I have notice that a little more when the ac is on and the car is cold . You dont want to trust it for a quick take off. If it continues it will be take to be serviced.
  • mterrellmterrell Posts: 21
    Well love the car! hate the the hesitation when you need power to pass or get out of the way. seems "there could be not always" a 3 or 4 second delay in down shifting from overdrive (D). Its is either the TPS or a trans relay. Has any one else notice this problem?
  • lirlir Posts: 81
    I have the 4 cylinder and haven't experienced that, but my friend has the V6 and is having that same problem. I also read people having that same problem in another forum. Looks like it can happen to 4 or 6 cylinder RAV4's.
  • petlpetl Posts: 610
    I'll be blunt. I don't believe there is a 4 second delay.
  • bob777bob777 Posts: 19
    When it first happened to me I was pulling out of a lane of traffic heading aross two lanes for an exit. The delay seemed longer than a couple of seconds to me and 4 is not out of the question. In fact it never did downshift that time, even with my entire weight/strength pressing the accelerator to the floor.
  • jimd4jimd4 Posts: 877
    I would think that is a real hazard and you should have a serious talk with your dealer if not with the National Highway Safety guys
  • mterrellmterrell Posts: 21
    Thats what mine did although when I let up on the gas it down shifted. It has done it to me twice .Once was when it should have down shifted and the other from a dead stop. I talked to dealer service and they have not received complaints. Because mine did this from a start at a red light makes me think something is going on with the tps .Just dont seem very responsive. I have almost 3000 miles on it and now its not just a break in deal? is it?
  • mterrellmterrell Posts: 21
    I have to say that going up to 89 octane has made a difference. Cost a little more but with the variable timing it make a noticeable difference.
  • bob777bob777 Posts: 19
    The dealer does not want to deal with the situation. They want to blame it on how I drive and not the car. The National Highway Safety folks is an interesting thought. Have you done this before? If so, what happened?
  • jimd4jimd4 Posts: 877
    have never done the NHSI stuff. But if enough people write it will get attention.

    But really, call the Toyota main number or write a letter describing your concerns. Let someone drive the car with you there and see if their style makes it drive different.
    Work on your dealer. Take it too another dealer. On the RAV4W site there are similar complaints but low numbers of them.
  • bob777bob777 Posts: 19
    I hear you and I am taking it to another dealer. But, Toyota is not reacting in a responsible manner on this.

    It does not happen all the time, but instead only under certain situations. I can and do avoid the lack of down shifting by doing it manually now, but I did not think of that when it happened the first couple of times. It was clearly unsafe those times.

    Toyota needs to fix this not me. They have enough input to know there's a problem. Also, I have written them. No action at all.
  • I have 4x2 4 cyl with 11500 miles on it.

    I am getting somewhere around 27-28 now highway miles, before it was around 24-25, with full load 20 highway.

    But now I the engine got very noisy.

    Haave most of the problems described on Edmunds forum.

    Windows rattle, i was told that it is a design flaw. Was fixed,noise came up again, they are going to replace the whole power window system.

    Electronics is glitchy. Had wird stuff with LCDs, nonreadable symbols. VSC and ABS were lit up for several weeks, cruise control didn't work until they cleared computer memory second time.
    These are hard to verify problems... I have to run to a dealer every time I see it, otherwise they wont believe me. They joked on my RAV4 saying I got Ford Explorer. And everytime I come to the dealer all management comes out and looks at the problems saying WOW this is first time we see it. liek it helps. Toyota Motor Corp does not want to do anything yet. Lemon law doesn't fit yet... So I have no clue what to do with it.
  • bob777bob777 Posts: 19
    Man, I wish I could tell you I've been successful with Toyota dealers. They seem to want to put the problem onto owners. The issues I have are with the lack of downshifting, breaks the faded even during the first hard breaking and gas mileage that was a bit low.

    I hate to say this, but persistency seems to be the key.

    They've, Toyota, seen these issues, but they have been able to put the proof onto owners instead of taking ownership of problems and solving them.

    I've had quite a few new cars over that last few years and I have not had anywhere near the same experience with them. I'm talking about Ford, Mazda, Nissan and even Chevy. I'm trying to figure out why people think so highly of Toyota.

    My gas mileage is starting to get better. I have over 8K miles on it now and it now gets over 24 MPG during mostly in town with some highway miles.
  • bob777bob777 Posts: 19
    Hmmm
    This is interesting. Thanks for the info. Should I be looking at something specifically? I don't find much on the Rav4.
  • lirlir Posts: 81
    For those of you that have had the throttle lag problem and have taken it in to the dealer to be serviced, was there a solution? a fix? Has the condition gone away? I took my RAV4 to the dealer today for that very reason, but the mechanic was not optimistic. He said that is a HUGE problem with the RAV's and there's been no recall. I am very upset because this is a big safety issue, I almost had 2 accidents yesterday, and had I known this, I would have never in my life bought this car. I'm hoping there is a fix and that maybe I hear a bit of optimism from you guys.
  • rickcorickco Posts: 3
    I, too, have the "lag" problem with my RAV4. Unfortunately, I have received the exact same response from the service tech at the dealership(others have reported this problem, but as of this date, there is no "fix"). I reported the problem on my second trip to the dealership and I felt it was "blown" off by the attendant even though it was written down as a problem. On my voice mail message from the tech saying my Rav4 was ready to be picked up, the tech said they could not duplicate the problem and no action was taken(the car was driven around three miles to try to simulate the problem).

    If anyone knows of a solution for this "lag", I would be happy to hear from you.
  • lirlir Posts: 81
    I got the same response that you got. The tech drove with me, and noticed it, but unfortunately there is no fix. He said the computer is getting used to my driving. That was funny! Anyhow, same answers I've read before (drive by wire). He said happens to a lot of cars. Oh well.
  • jimd4jimd4 Posts: 877
    I think lots of service guys BS on this topic at dealers.
    Two Audis, 8 years, almost 100K miles. Both "fly-by-wire".
    No lag under any conditions. The only way you know it is a computer throttle is that when you put cruise to 70 you can tell the pedal is not at 70 Mph position. It is at idle it seems.
  • lirlir Posts: 81
    I agree the dealers like to BS on this topic - I talked to 4, all gave me the same song and dance. I will see how the car behaves in the next week. I really love my RAV4, but if the situation gets worse, then I will reconsider selling it. Like I said before, it is the safety issue that most concerns me. So far today, it did not act up.
  • user777user777 Posts: 3,341
    try adjusting your foot position on the accelerator, specially if you tend to be more of a toe tip driver.

    i.e. move your heel closer to the pedal so more of your foot is in contact with the accelerator.

    some people in other forums report this has helped reduce the lag they experience.

    it's been a theory of mine and a few others that there is excessive slop or play (mechanical compliance) in the pedal assembly, and possibly it needs to be replaced...

    however, no one has had that done that i know of, and it is conjecture. there are many theories about there being a transmission problem, a programming problem, shift solenoid problem, throttle body problem. it's really hard for anyone to know.

    that said, one owner of another toyota model (can't remember if camry or avalon) modified their pedal to make it stiffer in some manner and reported an immediate improvement, but later, his problem returned. that coupled with the foot placement reports does seem to point to the accelerator assembly as a potential root cause.

    anyway, give the foot placement a try and see if it helps. good luck.
  • wwestwwest Posts: 10,706
    First,given the number of Toyota and Lexus vehicles (2002 and on...) appearing to be subject to this delay/hesitation symptom, mostly FWD or front biased AWD, and DBW, very few are actually incurring it.

    To me, that would most likely point to something unique those few drivers are doing, quite possibly, probably, exacerbated by a so-far hidden (deadlock/deadly-embrace) flaw within the engine/transaxle's ECU firmware.

    The issue of foot placement, to me, provided something of a clue. Back in the fifties we knew, learned, that automatics would upshift more quickly with a slight momentary lift of the accelerator pedal.

    It has also become pretty clear to me that almost all modern day vehicles have automatic transmission control firmware designed to extend FE via adoption of certain techniques put forward in an engineering white paper published by Sierra Research late in the last century.

    Foremost among those was something referred to as ASL, Aggressive Shift Logic. The basic idea was to upshift the transmission at every possibility and thereby reduce the engine RPM to extend FE. There were at least two others, one of them being the use of the torque lockup clutch in lower gears to reduce "slush pump" losses provided the engine wasn't under heavy load.

    The shop/technical/repair manual for my 2001 AWD RX300 clearly indicates the above two features are in use.

    My 2001 911/996 Porsche C4 has DBW, but a manual gearbox. Since it's predominantly RWD, and with a definite rear weight bias, I can use engine braking quite safely if I wish, even on a somewhat slippery surface.

    So, how do you "treat" your accelerator pedal when you simply want to coast down to a lower speed, maybe even come to a full stop, VERSUS how do you treat it when you anticipate a need, during coastdown, to quickly accelerate?

    In my case in the 911 I might downshift and then leave the clutch engaged (until almost stopped) but lift the throttle in either case. Were I driving a FWD and the roadbed a tad slippery I would no doubt disengage the clutch should I have one available.

    On the other hand were I anticipating a need to "soon" accelerate I would disengage the clutch while leaving the transmission in the most appropriate gear for the upcoming acceleration.

    The firmware designers at Toyota?lexus have a rather difficult task. The firmware must be designed to upshift the transmission at every opportunity, a 9.8% improvement in FE is not to be sneezed at. And not being able to forecast and with no method to detect a somewhat slippery roadbed except after the fact, their design bias will not allow them to allow a downshift except on explicit and "certain" commands from the driver.

    As User777 has said, higher foot placement on the accelerator pedal does seem to have had a positive effect. Posters trying this have said they have encountered fewer instances of delay/hesitation via using this method.

    Higher foot placement would mean needing more foot pressure for a give distance and shorter travel distance for a given throttle opening. It would also mean, very likely, QUICKER release of the accelerator pedal, and coupled with the shorter distance involved this might just be the rear clue we're after.

    I have no doubt, absolutely NONE, that the firmware is written to detect the difference in the release RATE, and/or partially released position of the accelerator pedal in order to determine the correct action to take with regards transaxle activity, shift up, down or remain in the current gear ratio.

    A quick, definitive, FULL release of the accelerator pedal would undoubtedly indicate a wish to coast down to a lower speed. Whereas a partial release, or a "slow" release, possibly even toward a full release, might be interpreted as a desire to enter cruise mode, in which case an upshift would result.

    So, the priorities become...

    1. Upshift for "cruising" whenever possible, feasible, for best FE.

    2. Upshift on the slightest indication of "coast down" to best prevent loss of control from engine compression braking's interference with ABS on the front wheels.

    3. Downshift ONLY with definite, definitive, action by the driver, action such that there can be no question but that the driver wishes to accelerate.

    See, the "deck" is stacked against you, quite firmly against you.

    But try the following.

    Do not "feather" the accelerator pedal in these instances, be a highly definitive "on/off" type of person/driver.
  • user777user777 Posts: 3,341
    But try the following.

    Do not "feather" the accelerator pedal in these instances, be a highly definitive "on/off" type of person/driver.


    you should only have to lift the foot off the accelerator pedal when applying the brake. if that doesn't work in these cars, it's game over.
  • wwestwwest Posts: 10,706
    As you drive along the highway sometime, look at how many, or really how few, drivers are cruising along NOT removing their left foot from the brake pedal.

    And I'm not saying you must remove your foot entirely from the accelerator pedal.....or maybe... I am....

    With a DBW accelerator pedal now with a light duty return spring, can we really tell that leaving our foot "resting" on the accelerator pedal isn't having the same type of effect as those that are clearly, unconsciously, applying pressure to the brake pedal?

    More and more I am beginning to think a heavier accelerator pedal return spring, or a "torque motor" might be the solution.
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