The problem is in the new RAV4 and the Highlanders too. 4 to 5 seconds is way too long, sounds like Tom H have other issues besides the transmission lag.

 

I tested the Highlander yesterday (just came to Mexico a few weeks ago) and I also noticed this lag. Salesperson said it could be the altitude, but I discounted that, I know when there is lag and while I could buy in part some altitude issues from accelerating from a dead start at a stoplight (which I did), once the vehicle was in motion at about 20 to 30 mph, and I would hit gas, it wouldn't immediately come to life. By my count delay was about 2 to 3 seconds. I had a similar experience a few weeks ago testing out a Mazda CX7.

I prefer a mechanic throttle like on my RX300 to this modern electronic throttle, as I really need, given the situations I have down here, to be able to accelerate quickly into traffic and move precisely when I need to, not have several seconds delay.

 

I don't think it is the Drive by Wire, or Throttle by Wire technology itself. I will admit throttle response with a cable properly set up probably is still much more responsive, but if you get the software right the DBW is just fine. Perfect case is the Acura NSX. It had DBW starting in 1995 I believe and throttle response on that car is not an issue. My BMW is also is DBW and while there does seem to be a slight dead spot at the very begining (Nothing major. Feels similar to a slightly slacked trottle cable) it still is very responsive with no lag).

 

Yeah, that's the whole thing. You are at the mercy of the software, but of course such drive by wire systems depend on it.

In the RX300, you can actually adjust the bolts on the the accelerator cord so the accelerator pedal is a little firmer and more responsive. I wish this could be done simply on the 2nd gen. RX.

 

My feeling on this lag subject is that it "good intention going bad" ... as the vehicle design moves towards more fuel conservation and safety (braking), the throttle has to be de-linked with the pedal. Number of gears, weight issues makes the problem multidimensional. We have to go through teething pain here.


Salim

 

It actually feels like the car is in neutral and waiting for the software to determine which gear it should be in. The engine revs up as I apply the throttle until it picks a gear. The faster I want to accelerate, the shorter the delay. I might add that it eases into the gear once it has selected one. It's not an abrupt or harsh shift.

 

The drive by wire system is here to stay, since all vehicle that have stability system needs to have drive by wire system.

 

Thanks Tom. By the way, how many miles do you have on your RX?

 

Still new at 550 miles.

 

Tom, I am sorry to hear about the issues you are having with your brand new Lexus. Is the issue easy to reproduce? Would you be able to video it without getting in an accident? I would really like to see exactly what happens from the driver's perspective.

I have been able to video my Camry's shift flare several times. For me the easiest way was to hold the camera in my right hand, lean over a bit and rest my hand and camera on top of the steering column as I drove. Once I got the tachometer and speedometer in view, I could forget about them and drive without being distracted.

 

I also have the 'gear hunting' problem as described. It is very minor, about 0.5 to 1 sec lag, as it tries to find the right gear during low speed acceleration. I can always replicate the issue during a rolling stop: let go of the gas pedal then cruise 30-20mph then accelerate). The transmission shifts a bit harsher in that speed/rpm zone, the feeling best describe as 'shift shock' for lack of a better terms.

This issue is well discussed and documented on RX330s. Even after Lexus transmission software update that supposedly fix the complains, many owners are still dissatisfied. Apparetly, Lexus has not been able to solve the issue 100% eventhough it is less pronounce on RX350s than on RX330s'. The RX400h does not have this issue because it uses CVT.

Dont be mistaken, this is not buyer remorse from my side. I am aware of this issue before I purchased RX350 as I have driven them as loaners for 300+ miles in total. I will still buy RX350 over my other 2 choices (BMW X5 or M-Class).

Here is a work around that I notice will 'force' the transmission to make up its mind while gear hunting: very lightly feather the gas pedal to give more rev, and the transmission will find the right gear immediately.
(disclaimer: please try this on empty streets first, I am not liable if you loose control of your RX because of sudden acceleration!!)

My GF test drove the 2007 BMW X3 and similar issue exist, but much MORE pronounced (read: worse). Go to bmw forum and you will see lots & lots of complains on this. Even with software update, X3 DBW system is still "stubborn".

 

Thanks SugarRush. I have a 2007 Tacoma and I think it does the same thing - 0.5 to 1 second delay as the tranny hunts for the appropriate gear. It is a little annoying for me but not a big deal. The tranny must automatically downshift to 1st gear - thinking that we are going to make a complete stop. When we don't and hit the accelerator, it takes a while for it to figure out that it needs to be in, say 3rd gear.

However, Tom's 4 second delay is unacceptable (imo). I would take it to the dealer, reproduce it for them, make sure they document that the technician confirmed the issue in the Repair Order, have them fix it and have them document what they did to fix it. Keep very good notes and all your documentation - just in case they can't ever fix it and you need to pursue a buy back. This is a serious safety issue. According to the California Lemon Law, they only have 1 or 2 chances to fix safety issues.

 

I agree teamtbo, the 4sec delay is unacceptable to me. Even 2 to 3 sec is a big concern. I will give my dealer an opportunity to try to correct it but from reading all the posts it looks like Lexus has not been able to resolve the underlying design issues. I follow the GMC Acadia forums and they have similar issues trying to get the transmission to respond correctly. Ironically, my wife's 2007 Camry XLE doesn't have any perceptible delay that I've been able to detect. I'm not really thinking lemon law at this stage but in Indiana the manufacturer gets three attempts to fix a given issue. I will definitely be sure the technician documents the complaint and the attempted resolution.

I appreciate the responses from everyone on my call for help. Obviously, I'm not alone with this problem. I was somehow hoping my first Lexus purchase would be a rewarding experience and without problems. Its not been the case so far. Where does a person go from here? Lexus is supposed to be the best. I have to say this is a bit of a disappointment but I'll be patient and civil and see what can be done by the dealer.

 

I really dont like seeing people waste their time, but the dealers really dont have much of a fix for this. They will suggest doing the software update which will in most cases make it worse. The next time you bring it there they will let it sit in the shop and then give it back to you saying that it is in fact normal. The dealers will most likely try and tell you that this is normal, if you can get them to admit that it is not normal they will tell you that they have done all they can. At that point which is where im at, the dealers will tell you that until lexus HQ decides to do anything else their hands are tied. the 4 second lag isn;t that crazy, my rx330 does that every now and then, it feels like it cant find the right gear, then all a sudden it finds it. Ive taken mine back 3 times now, my mechanic (independent) owns a 2005 rx330, they have brought theirs back 4 times now and each time its the same thing.

 

AM1,
I suspect I will get the same treatment that you have described but I should at least register the complaint to do my tiny part to keep it front of their face.

One of the things I think is excellent and unique about the GMC Acadia trans issue is the actual engineer who is doing the software programming visits the forum regularly and communicates to the owners his progress. He asks for dialog on what they are experiencing, tells them when the next software release is due and what to expect. What is very interesting is that he often says the next release still isn't perfect but so and so issues are improved. What a great public relations move on the part of GMC. This goes a very long way towards calming the owners down and giving them a strong sense that they are being taken care of.