my problem is also from 2nd-3rd gear and also in stop and go traffic. i dont know what the deal is, but it seems like im not the only one with this problem. If anyone ever finds out wat the problem is, dont forget to let us CL members in on it.

Boris

 

Well..I've a '99 GS300 and I'm not sure if I've the same thing. The hesitation and sometimes jerk happen most when driving uphill with low speed. If full throttle then it will be fine. It's very annoying. Anyone has a cure for it?

John

 

That's the problem i have. In my 2k1gs3, 6000 miles, when coming home, uphill, turning into my driveway at slow speed, slight hesitation then sudden surge/shift. Almost impossible to smoothly turn into my driveway. This problem has been there since the car was brand new and is still there. I hate it. Otherwise, dont really have the 2nd to 3rd problem being reported.

Anyone else notice this? What can we do?

 

I have an '01 GS3 with 9000 miles on it and have never experienced a problem such as this. Lets hope this continues.

I used to own an Integra GS-R which used to have this problem to the extent that I did some research on electronic transmissions.

E-transmissiong, an opposed to hydraulically governed trannies, utilize primarily 2 electronic inputs to determine which valve to activate thereby selecting the gear. These 2 signals come from the throttle position sensor and the vehicle speed sensor. Hydraulic transmissions utilized governors and hydraulic pressure acting on larger surface areas.

In the Acura, I observed the greatest frequency of shift shock problems when in stop and go traffic. Trying to keep up with the car in front of me during rush hour, I observed that if my accelerator pedal (which is linked directly to the Throttle position sensor) was in a certain position at a certain speed, the transmission would hesitate as it decided which gear to select, and then would simply SLAM into one or the other. VERY IRRITATING. In order to correct the problem, I just started managing my throttle position ie. foot pedal (shifting at a greater RPM) and the problem was avoided. I figured out a long time ago that a dealer will only go so far out of their way to help you.

I suggest the following tests?
(To eliminate the problem, you must turn the problem on or off.)
- Does the problem happen in both Power and ECT mode? (The power mode calls for a more agressive shift pattern)
- Is the trans fluid OK?
- At what SPEED does the shift shock occur? Maybe a specific range?
- Outside Temperature?
- VSC ON/OFF?
- Can you try shifting at various RPMs to see if the problem happens only at a certain speed?

My transmission has never done this..hope it stays that way. However, my drive to work is 10 minutes now and I have NEVER been in stop and go traffic for longer than 5 minutes in my GS...

Hope this information helps...

 

YES there is a shifting concern on the 01 gs3 and is3 only.The GS4 and ES300 01 has a differant trans. and programming. Not all the cars(gs3 -IS3) are affected. Disconecting the neg. cable for 5-10 min. does help. I know that Lexus is working on this so bear with them,It is not worth going to court or getting into a diiferant make, Lexus is still the best and y'all know it. There isnot a TSIB out on this yet,but I bet there will be soon

 

the hesitation i get is usually at a certain throttle position, usually low RPM's and when it changes gears at higher rpm's i avoid this hesitation. but sometimes its hard to avoid in stop and go traffic because i dont want to be hitting the gas very hard and then slammin on the breaks. Hopefully lexus will come up with an answer and fix this problem for us

Boris

 

Thanks,

I agree it's the best, that's why it's been so frustrating! If Lexus would just recognize a problem exists, and say they're working on it, all of my previous posts would have never happened. The delayed response and shrugging of the shoulders and a "get used to it" attitude is what I resent. Believe me if I could have found a better car, this one would have been history a long time ago. Only after finding out, again, that this was the right car for my wife, did I decide to not let this go. Hope the TSIB is soon.

 

Finally got over to McGrath yesterday. The Master Tech who works with me (11 years experience with Lexus) had seen this problem at least twice on a '99 and '00. He recalled that on the '99, they replaced the tranny, and the problem returned in a few months, so this is not the approved procedure. He did not recall the '00 results.

As per the norm, he was unable to duplicate the problem on my car. He called the regional and two Lexus numbers in CA, and this was their suggestion. Pull the # 34 ETCS (electronic throttle control system) for five minutes to reset the computer. He said that popping the battery cable would accomplish the same thing, but would change all of the electronic preferences.

I will report back with any further impressions.

 

I know some of you are are not going to like this, but most of you are tilting at windmills.

I'm sure there are a few transmissions out there which are defective, but virtually all of the newer model auto transmissions in all cars exhibit this behavior to some extent. These transmissions are electronically controlled and have a number of inputs. The transmission has feedback loops to the engine timing computer, the FI system (which has a "no gas" speedown idle shutoff to improve fuel mileage and emissions), and the VVVTi system (which mechanically must rotate the cams to a new position). All this stuff had small delays which can propogate in weird ways. This is the why the problem seems to come/go. It is not because a "fault" comes/goes, it is because every time you accelerate and deaccelerate, you are traversing different paths through the system since you never accelerate the same each time.

As to the transmission "slamming", I'd use the behavior in steady state acceleration to determine this. Drive you car at various steady acceleration rates and see how it engages each gear. If the shifts are reasonably smooth, then your transmission is fine. MAKE SURE THE CAR IS FULLY WARMED. The car also includes a system to delay shifts and rev the car more when it is cold, so if you're getting "slamming" behavior when you first drive the car out of the driveway, it may just be the system wanting the car to rev more to hasten warmup. If the transmission does slam under normal acceleration when warm, you need to bring it up with the dealer.

There have been some ECU mods that help (I've had two on my early-prod 98 GS) and there are some service bulletins out. But I think when you are into late 99's or 2000's, then you probably have the latest/greatest software. It certainly wouldn't hurt to ask the dealer to look up the latest SB's on this problem and see if there is anything that improves it. Just don't expect miracles - my early 98 had the problem BAD and the first ECU six months later made a huge irmprovement. But the 2nd didn't make much differnnce at all and the dealer warned me that it wouldn't. In fact, he wasn't supposed to even install it as a fix for the problem, but he did it anyway. My car still does it a little, but I've simply accepted it as part of the behavior - it really isn't a big deal.

My experience is the the PWR mode makes the problem worse since it tells the transmission to shift more aggressively and to hang onto shifts longer. If you inching along in stop-and-go traffic, the last thing you want is more shifting and more aggressive shifts.

My experience is also that keeping the transmission selector in 4th helps, except when up to speed on the expressway. This locks out 5th gear and reduces shifting. You might be flabbergasted how soon the transmission shifts to 5th - at anything over about 20-mph it will shift all the way into 5th, which means than any acceleration or a hill will require a LOT of downshifting.

Finally, most CAN modify their driving habits to help the problem. The idea is that you want to avoid jacking the throttle around and reacting to the hesitation by backing on/off. Transitions are the problem. f you're a freeway driver who is right up the tail of the guy in front of you, you'll be modulating the gas a lot which is the problem. When you press on the gas to go just a little faster, give the car a little time to respond, hold the throttle where it is, don't press harder when you feel the hesitation as you're just changing your request on the system which has to decide to find another gear, change the valve timing, etc. Smooth is the word.

As I said, all these new, complex, sophisticated cars do this sort of thing to some extent. Some are a little worse than others and I hear the most complaints about the Maxima and the GS. Lots and lots of people complain. If you really can't live with it, I'd trade, but just because the Audi, or BMW, or whatever seems to not do it on the carefully arranged test drive, doesn't mean it won't be just as bad when you are slogging through traffic with it. It may just be easier to modify your driving to be a little smoother and move on with life and enjoy the car for all it does offer which is considerable. Despite Lexus' "Relentless Pursuit of Perfection" are cars are a long ways from perfect.

Sorry for the long post.

- Mark

 

Has anyone here considered that this intermittent condition just might be NORMAL for this particular model.

1. A trans that shift lazy to begin with
2. Drive by wire system
3. No kick down cable anymore
4. Learned memory in the shifting, which gets worse as two different people drive the car regularly
5. Only happens when CERTAIN conditions, that nobody can pin point, exist
6. Happens to almost every owner!
7. No adjustments can be done to the trans, externally.
8. No transmission codes ever stored in the engine ecu
9. A beat to death topic!

Need I say more.

My 2 cents

 

Ok, so this problem is a much larger one than Lexus thinks, why are they not stepping forward to at least acknowledge this problem ? Will our warranty on the powertrain help in future if the tranny goes t*ts up ?

Have to be honest considering another make, perhaps the BMW 530i

 

Though this problem drove me nuts, it hasn't happend since the weather turned cooler, or we went over 10k miles It will be interesting to see if it reurns when (and if ) it warms up again!

 

my 2000 gs3 does this too....but it also slams!!!! into gear when going from Park to Drive or Reverse to Drive.....What to do?????

 

I had the same problem in my Gs 400 for the past year, Last night I took out fuse # 38 I think, It's the 25 Amp that says EFI. I left it out for 5 minutes put it back in drove for 500 Km only took 9 hours and My car feels like new again. No more slamming into gear, or anything like that hop it lasts for a while!. You guys with this problem should try this out then post your results.

 

See, what'd I tell y'all!!!!

#38...easy to remember. Just think 400 minus 300 minus 62.