konradsa

So far I haven't noticed it on our 2013, but we only had the car for like 10 days.

vlad_a

Not having problems with my 450h. VDIM is very well tuned. It also has no traditional transmission (it has Power Split Device).
Technically speaking, relative to this topic, buying a modern car would be a deal breaker then.

StillLine

My wife and I have had our 2010 RX350 FWD for 16 months and 15K miles without a hiccup. I don't see that these acceleration hesitation problems are an "across the board" issue. I hope the few folks who are concerned/affected get some satisfaction.

mcdgary

I asked a 2010 RX350 owner as we exited our vehicles at a bank if she was familiar with the hesitation/acceleration problem. She was quite familiar with the problem having put over 35K miles on her 350 since purchase. She said she had just learned to live with it.

If I could only find a unique condition in which the problem occurs, e.g., making a left turn from a secondary road to a primary road and accelerating due to not interfering with an oncoming car repeatedly I would have a case to present to the Lexus Service department. I have tried unsuccessfully to re-create the condition to onset the problem. Therefore, the Service Dept. is simply going to tell me, "We did just as you stated and we did not have a prob elm, see ya."

mcdgary

In my 2012 RX350 the Trac on/off switch is located on the Center Console on the left just in front to the Console Box. If it is turned off a message will be shown on the multi-information display. The Owner's Manual states that to turn Trac off simply put the switch in the "off" position. When it has been turned off it will come back on when speed increases. To turn Trac & VSC off is different. Also, if both are turned off they to not return to "on" as speed increases.

Droid13

I had 2 days with an RX350 when by RX450h was in waiting for a part. I experienced this issue a few times, and I immediately thought "classic Toyota automatic transmission". My now 10 year old Sienna has exactly the same issue.It was quite bad in 2003 when I first got it, about a year or two later they back installed the 2005 firmware onto the 2004s to make them reasonably tolerable. When i happen to be out and about with the Sienna and want it to be responsive, I simply use the shifter to keep it in the right gear for the occasion. Fortunately the Sienna has a nice gated shifter setup which makes it easy to manually select gears while driving. Everything I've read here I attribute to electronic control of the transmission. And why it's not "fixed" years and years later though widely experienced, because it's not something that is fixable, but a design choice with trade offs that is being made. To get good mileage numbers and quiet smooth running vehicles, these things are programmed to hunt the highest gear possible which is the exact opposite of responsiveness, where you want to be in the lowest gear possible. How to get from the highest gear possible to the lowest gear possible without over-reacting or under-reacting is the next challenge. Some cars lag and hestitate, others that just with a modest amount of gas pedal pressure decide it's time to drop too many gears and redline the engine (and people look at you saying WTF is the ahole doing).

There are some cars with decently responsive auto-trannies, I remember a Dodge Charger rental I had, the thing would aggressively hunt back and forth in the gear ranges so it felt responsive, but for someone wanting a pleasant smooth ride, it would not feel "civilized".

I just don't do automatics anymore, they annoy me for the most part. My primary driver has been hybrid for 7 yrs now, and while they are not necessarily the most responsive, they are consistently responsive. Problem solved for me. I think the problem has gotten worse the more gears they keep putting in these things. Back in my youth 2 and 3 speed automatics and a simple mechanical downshifter was all you needed, no problems, but terribly inefficient. Once these things started hitting 5+ gears and some software trying to predict the future, it all went downhill. The problem will be fixed when the tranny AI can see into your future by a few seconds, or at least plug into your brain to sense your intentions before your brain even tells your foot to move...

Google self drive, bah... Jack me in Neo!

vlad_a

Now that I think about it, I test drove the Highlander Limited prior to buying the 450h. First thing it did was left me without power on the very first turn out from the dealership. So, I stopped at a parking lot to find the Trac off button, so it wouldn't "interfere" with the test drive. I do not recall if Trac re-enaged at certain speed. My 450h will turn it back on after hitting either 25 or 30 MPH.

BobBass

Droid13,

Yours is one of the best and well-reasoned posts I've seen on this topic.

Too bad there isn't a resolution, although I must say with my '08 400h and CVT I have NOT experienced it. Neither with our '09 TCH.

Boris2010

I had this problem until I returned RS350 2010 to the dealer. Although I should say that it happened much less frequently in the third year of my lease.
My latest car is RX350 2012 does not exhibit any transition related problems - the run of this one is smooth and powerful: there are no hesitations of slipping.
Now I can for sure that problem that made me start this thread was absolutely related to the on-board computer settings.

mcdgary

As I stated above mine is also an RX350 2012. Was your "latest car" pre-owned that maybe had the issue and returned to the dealer for a "fix?" My RX350 had only 650 on the odometer when I bought it in April and was most likely one of the dealer's service/loaner cars.

viperdoc

I must agree with Droid13. My F sport has 8 gears, which I think I like. THe shorter gearing does make the manual mode more fun. But I have noticed that downshift delay as well. I fixed mine (for the most part) with an Apexi throttle controller. But sometimes I still notice it.

One thing I did notice, and I assume it is designed this way, is that in the automatic mode, even when I am going at a snail's pace, when I shift the gear lever over the manual, the car is already in SECOND gear. And I am going VERY slowly- like under 5 MPH. I reasoned was that this was to avoid excessive shifting when you start going from a standstill. But the problem is that even when you are going very slowly, to accelerate briskly, the car still has to downshift at least one gear. At 30mph, I shift over to manual, and I am already in 6th of 7th gear. So it's no wonder why there are such regular downshifts, and because of that, there are delays. I think, like Droid13 said, this is due to the 8 gears. It's almost like in auto mode they wanted to hide some of the gears to people wouldn't get annoyed with all the shifting anytime you went from 20mph to 25mph.

That being said, 3-4 seconds is a bit long. Like others have said, I would get it checked out. Perhaps the electronic sensors in the pedal or the throttle body are bad? If everything checks out and you are still bothered by it, check out one of the throttle controllers. They work wonders.

titch

After much arguing and negotiating with the dealership, they took back my 2012 and got me into a new lease on a 2013, although they never admitted there was a problem. We had to pay around 5k in penalties, but we were willing to do so in order to get rid of the vehicle. Every month that this went on, we were losing money as we were obviously not going to keep the 2012 beyond the lease. My 2013 has been running beautifully since we got it last Nov - no issues at all.

mcdgary

I returned to the dealer for the first time since buying my 2012 RX 350 for the 5000 mile warranty maintenance service. I specified the numerous encounters I had had with "hesitation" on acceleration. After the maintenance service, the Tech test drove my vehicle several miles in the area to test my problem. As I expected it would be my bad luck for it not to occur. I was told the problem would be flagged on my service record such that they would be aware if the issue continues. It has not gone away, but until I can consistently duplicate the situation of occurrence, which seems unlikely, I'm stuck. btw I did notice when it occurs the tachometer does not increase with increased gas pedal. It's a momentary stall, therefore, it's not a transmission issue IMO.

corradoMR2

Could be the ECU that needs a reset so it re-learns your driving pattern and hopefully hesitation is corrected. Has the dealer done that? if not, might be worth a try. Easiest way is unplug connections to the 12V battery and re-plug after a couple minutes.

CapeDave

A agree, great post. I seem to have this issue at one spot where it is an uphill right turn with a stop sign before turning right. Not really a T. More like a Y.

But I do notice some hesitation as the car does seem to stall, rather than be looking for gears. It is freaky. I am hesitant to floor the pedal as that would possibly LURCH me into traffic which could be a bad thing at that intersection.

I am going to pay very close attention. It may happen at other times but for whatever reason does not seem to be as noticeable.

I agree that this continual addition of gears which is really just another form of oneupmanship that is unnecessary at best is a TOTAL FREAK SHOW. Coming soon, 11 gear sedans to your garage

At my age a manual is out of the question, but maybe a Hybrid would be the answer?