Thecar

I have only had this car for a few weeks, so this question might just be a bit noob-ish.

When I am in "normal" drive mode, I tend to be pretty light on the throttle. I notice that when I accelerate from a stop, the tach revs to around 2000 rpm, and then several very quick shifts happen around that engine speed. When each shift happens, the tach only seems to drop 100-200 rpm at most. Then, around 45mph or so I end up in what I think is 6th gear at about 1300 RPM.

Sometimes, I also notice what seems to be a downshift that happens in the middle of this sequence (i.e. the revs go higher by about 200 RPM and the car noticeable jerks forward in faster acceleration). It's almost like sometimes the car cannot decide which gear it wants and goes back and forth.

Today I tried the manual shifting mode, and all the shifts were normal when I requested them.

Does this seem abnormal to anyone else? Is the transmission just close-ratio enough where the 2-3-4-5 shifts do not drop the RPMs by very much?

The car has 130,000 miles and there is no indication in the records of any transmission service (and the Lexus service records go all the way to the present, pretty much).

Another question: Does anyone have a spec sheet for the 6-speed transmission that shows the normal shift pattern? I can find one for the 5-speed on google, but no luck finding one for the 6-speed.

2KHarrier

Pretty much normal. My 2005 with 59K on it will go through the gears pretty quickly and as long as I'm not getting on the throttle too heavily, I'll be in 5th gear by 30-40 mph. 6th gear comes along right after that.

If you accelerating more "Aggressively" the shifts will be spaced out more, as the engine is asking for more power between each shift.

My 2001 has 194K on it and shifts the same way.

Thecar

I was hoping it was just an LS thing. I've never driven an automatic with more than 5 speeds, and my last one was only a 4 speed.

2KHarrier

I missed the second part of your question... About the shift pattern.

I found this, which shows the shift at WOT, but that's not very helpful for normal driving....

This does explain a little about the differences with the Snow setting and Power settings though....

Thecar

Awesome, that's what I couldn't find. I doubt there is a chart for non-WOT, since how would you measure the amount of throttle your foot was giving it anyway?

2KHarrier

Good point. It would be infinitely different depending on how far you pushed the pedal down each time you accelerated.

In any case, this trans likes to get into the higher gears as quickly as possible..

Thecar

Lol, when I push the "power" button, the RPMs go all the way to 2500! In contrast, my 3 series feels like I am lugging it at 2500 RPM.

Anyway, I drive the Lexus like a grandpa when my kid only just turned 4.

jayclapp

Forgett about it! Just drive the damn car, let it do it's thing. If you have to look to see what gear it's in, that means you can't sense and keep up with the gears. So, why even be concerned? Just enjoy one of the best cars ever made.

Thecar

Well, I did buy the car precisely in order to experience a lack of sensation of shifting (or really so that my wife can experience same), so not sensing the shifts is a feature, not a bug. In my defense, I have driven manual transmission vehicles almost exclusively for years, so I have become quite **** about knowing where I am in the shift pattern.

I do so much enjoy the car, though, even if the shifting feels a bit crazy to me. At this point, I think we just have to assume Toyota knows what they are doing when it comes to cars, huh?

AJT123

Completely normal. Funny, to me that's part of the appeal and what I love about the powertrain. I personally love how it melts through the gears at around 2100 RPM with plenty of torque--that's how luxury cars should drive....effortlessly. I wouldn't change a thing with the gear shifting pattern.

Mbodall

I know I'm digging up the dead with this somewhat old thread, but I can't believe that no one actually correctly identified your issue. I have an '04 with the same 6 speed and was having this exact problem. It was driving me nuts that the car was 'stumbling' because it was upshifting too quickly under light acceleration, causing it to drop back down a gear. I also had some intermittent hesitation/slightly jerky shifting at low speeds like in stop-and-go traffic or rolling around in parking lots, as well as the occasional rough downshift into first. There is a TSB (technical service bulletin) for these 6-speeds in 2004 models for sure, and I'm pretty sure it affected 2005 models as well... maybe even all '04-'06s. If you go to a dealership and tell them you want the shift logic reprogrammed, they'll charge you about $150-$180 to re-flash the ECU and update the shift logic to a new version. Copied from my receipt from Lexus, it shows as "Performed TSIB TC006-04 ECM Calibration: Shifting Enhancement, recalibrated ECM and ECT control modules".

After having that done over 2 years ago, car doesn't stumble anymore and feels a lot less 'sluggish'. It holds gears when accelerating just a little bit longer... almost like putting the trans in "ECT Power" mode but not quite. I seriously couldn't be happier with how the car shifts after having it done.

Thecar

I'm always watching my dead threads in case they come to life again! I could try the dealer TSB reflash to see if that helps, although I will say I have kind of just gotten used to it now.

Mbodall

I would definitely do it. It was worth every penny to me and made driving even more enjoyable and smooth.

BCT

FWIW, I was at local dealer picking up some supplies. I spoke with one of the service advisor re TSB. He recommended to drive it for a bit first. My situation is maybe a bit different. I just bought an LS which had been driven very little in the last few years. I do not notice anything with how it shifts, but then again I am not paying too much attention yet.<br /><br />He said that usually these TSB do not make much difference and I feel that he is steering to not have it done. Kinda weird this is coming from a service advisor - surely Lexus knows more than this guy. Maybe he is trying to save me some money (which I appreciate)? If they decided to produce a TSB, that means that there is something to be fixed/changed. Lexus is not going to produce a TSB just for fun lol<br /><br />He quote me $200 to get this done. I said I will think about it. If I am getting this done, I may work with different person.

Mbodall

He may just be trying to establish what he thinks is a realistic expectation. I should have made something very clear... I'm **** retentive when it comes to my car and how it drives. I'm very, very in-tune and connected with my car and can feel the slightest of changes in sound, handling, acceleration, vibration... everything. My car is basically an extension of me. If you're not the kind of person to notice the more subtle details, then maybe having the ECU reprogrammed isn't for you. My ex-girlfriend definitely didn't notice when I had it done, but she's the kind of driver that can drive with 4 flat tires and not notice. She exclusively drives the car every day for 1-2 months while I'm out on the road (I'm a long haul truck driver) and a few weeks ago when I was home I noticed my subwoofer stopped working. I asked her how long it's been not working and all I got back from her was "huh?? I didn't notice"... lol. Maybe that service advisor has had people (like my ex-girlfriend) come in asking for the reprogramming to be done "just because they heard it was available" and not really because they noticed degraded driveability, and complained after paying to have it done because they couldn't feel any difference.

I suggested having this done to the Thecar because he definitely seems like he's similar to me. If he's the kind of driver that made all these observations about his car's behavior when accelerating, then he'd definitely notice and appreciate the reprogramming.