Lag/throttle transmission - short term fix (please test)

[Joe T]

The pep has seemed to stay but its now bucking again at moderate speeds coasting. It thinks it extremely important to lockup the torque converter immediately (mpg BS) which is extremely uncomfortable and distracting.

Poll, should I just say F it and put the 0w-40 in it this weekend and flash the computer with the tuner? If it does anything weird like revert anything I am not going to be happy.

I hope some autistic s*** isn’t going on with efficiency or PCS settings: Per AI: A computer virus is a type of malware that attaches itself to other programs, files, or code, and then replicates itself by modifying other computer programs.

Keyword LX600 and GX550 review

 

[Docyota]

The pep has seemed to stay but its now bucking again at moderate speeds coasting. It thinks it extremely important to lockup the torque converter immediately (mpg BS) which is extremely uncomfortable and distracting.

Poll, should I just say F it and put the 0w-40 in it this weekend and flash the computer with the tuner? If it does anything weird like revert anything I am not going to be happy.

I hope some autistic s*** isn’t going on with efficiency or PCS settings: Per AI: A computer virus is a type of malware that attaches itself to other programs, files, or code, and then replicates itself by modifying other computer programs.

Keyword LX600 and GX550 review

Dude, take a chill pill. The lx600 doesn't have perfect transmission tuning, and I expect neither does the lx700h. Don't wig yourself out trying to make a vehicle perfect... that doesn't exist.

 

[EscapeWagon62]

The testing continues. There is no doubt the delayed throttle/transmission response is improved with PCS off. It is improved, but not quite as good, with PCS on minimum distance setting
Also of note - these settings work better in Normal drive mode vs Sport/Sport+. No doubt this means that some reprogramming (once developed by Lexus) will make these rigs even better
On an unrelated but often mentioned gripe - rumbling at idle when fully stopped. Noticeable improvement in Normal vs Sport as well most likely due to the different RPM at idle settings for these modes.

Overall I’m quite happy with PCS minimum distance and only tuen PCS off if I’m in very congested city driving.

 

[gerryvz]

After more driving, I can concur that “minimum” PCS setting helps — but does not eliminate — the issue.

 

[CyanideRide]

Here is what the Lexus tech said when I brought it to their attention this past weekend:

ROAD TESTED FOR TRANS CONCERN. NOTED THAT WHEN DRIVEN AS
DESCRIBED - COASTING TO STOP THEN ACCELERATING, VERY SLIGHT
DELAY BEFORE DOWNSHIFTING - HOWEVER PLEASE ADVISE THAT THIS
IS NORMAL - DROVE ANOTHER LX TO COMPARE - SAME CONDITION.
ADVISE THAT THE LX600 IS EQUIPPED WITH A 10-SPEED
TRANSMISSION, IN INTEREST OF FUEL ECONOMY, ECT LOGIC IS
WRITTEN SO THAT, WHEN STARTING FROM STOP AND LOW SPEED,
TRANSMISSION IS SET TO A HIGHER GEAR TO KEEP ENGINE SPEED
LOW. WHEN ACCELERATOR IS PRESSED HARDER, ECT WILL DOWNSHIFT
FOR POWER, HOWEVER BETWEEN THE ELECTRIC THROTTLE BEING
PRESSED AND ECT RECEIVING SIGNAL - THEY MAY BE A SLIGHT
DELAY FRO THIS TO HAPPEN. WHEN COASTING AT A LOW SPEED, ECT
WILL KEEP TRANS IN GEAR (4TH OR 5TH OR EVEN 6TH DEPENDING ON
CONDITIONS) THEN WHEN ACCELERATING, WILL KEEP IN THAT GEAR
UNLESS ACCELERATOR IS PRESSED HARDER, THEN ECT WILL
DOWNSHIFT FOR MOPE POWER. PLEASE ADVISE THAT THIS IS AN
INHERENT CHARACTERISTIC OF THE 10 SPEED TRANSMISSION AND THE
"FLY BY WIRE" ELECTRONIC THROTTLE AND CANNOT BE AVOIDED

 

[Joe T]

It actually hurts the fuel economy as it is relying on extra motor output to get moving.

You can tell they really chugged the Kool-aide.

Seems like a tuning engineer lost his argument or was a pushover. “Don’t care anymore just tune it goofy like they ask”.

 

[4les]

It's a hickup600 cause it never rolls smoothly from standstill

 

[EscapeWagon62]

It’s fixable
Just time and persistence.
I was at my dealer this week but the primary tech I use was on vacation. I’ll bring it back in a week or two as he plans on filing an updated tech case with national. He’s a respected tech who sits on some national advisory boards.
In the short term I’ve found PCS set to minimum makes it a pretty solid rig, I turn it off in rare instances (like roads with multiple rotaries where the poor programming in the transmission is most noticable.

I also find the condition is more acute in sport and sport plus. I’ve been running normal and comfort and its better. Side benefit is that im clearing 19mpg on three tanks of gas.

 

[Sinister]

It’s fixable
Just time and persistence.
I was at my dealer this week but the primary tech I use was on vacation. I’ll bring it back in a week or two as he plans on filing an updated tech case with national. He’s a respected tech who sits on some national advisory boards.
In the short term I’ve found PCS set to minimum makes it a pretty solid rig, I turn it off in rare instances (like roads with multiple rotaries where the poor programming in the transmission is most noticable.

I also find the condition is more acute in sport and sport plus. I’ve been running normal and comfort and its better. Side benefit is that im clearing 19mpg on three tanks of gas.

I too find it not perfect but don’t even really notice it anymore (and it wasn’t terrible to begin with) but I keep mine in Normal and sometimes comfort and also have the PCS set to min.

 

[Oakleyguy]

Interesting tidbit for what it's worth, although I haven't seen anything yet for the LX:

Technical Service Bulletin for the GX: L-SB-0042-25

 

[Joe T]

All they have to do is set 1st gear downshift at around 7.5-8mph. Then send out a TSB saying if they jitter or vibrate to run 0-30 or 5-30 motor oil. Also fix the key card to work with the rear gate.

Anyway, the sloppiness and delay is for transmission longevity purposes. And thats why it slams because you need the power abruptly.

The holding in higher gear is possibly because of 2 things caused by taking too much Tylenol while pregnant:

They truly drank the cool-aide without the wink wink and are doing everything in the text book to improve efficiency (higher gear less fuel).

They miscalculated some table on torque available because they do not understand how a small gas turbo engine works. My 5.0 F150 work trucks downshift into 1st at around 7-8mph. These are geared almost exactly like an F150. My 6.7 Ford Powerstrokes with ~1,000ft/lbs downshift into 1st around 3mph, and ford accommodated this with good programming so you don’t notice it. Although I think it downshifts at a higher speed with a heavy load.

 

[Joe T]

There is also some proportioning valve in the valve body most of these new light trucks have that controls pressure in the torque converter for comfort or some s***.

From the videos I have watched with Nextgen Drivetrain that valve is problematic. Gives the “square tire” feel when accelerating from a stop, which mine does cold. Also causes some shutter issues sometimes. They just eliminate it.

Also the valvebodies are built really cheaply in the domestic trucks and there is no reason Toyota wouldn’t follow suit since they are direct competitors.

 

[Joe T]

I too find it not perfect but don’t even really notice it anymore (and it wasn’t terrible to begin with) but I keep mine in Normal and sometimes comfort and also have the PCS set to min.

Do you regularly drive other vehicles? That may be the issue some of us have because the 2-1 shift in the lx is “uncanny” to say the least.

 

[Sinister]

Do you regularly drive other vehicles? That may be the issue some of us have because the 2-1 shift in the lx is “uncanny” to say the least.

No, just my wife’s X5. And yes there is a difference between the 2, absolutely. I just really don’t notice it a lot on the LX.

 

[Docyota]

No, just my wife’s X5. And yes there is a difference between the 2, absolutely. I just really don’t notice it a lot on the LX.

I concur. I've driven everything, and everything requires a little modification to my driving style for that vehicle's nature.

When I had the LX600, I just took off a little more slowly from a rolling stop, and it rarely happened. Mostly fixed in my lx700h.

 

[snowman69]

I say this with love. Toyota should be ashamed for ashamed for the s***ty transmission logic and the fart sounds the hybrid makes when the engine turns on. Other expensive suvs have zero problems with both of these things. X7 - perfect. GLS - perfect

Now I’m still buying my 700h because both of those other cars are pure people movers but still. Excusing Toyota is pure cope.

I think I’m going to fedex a respectful letter to the chief designer about these issues.

 

[Obi Wong Kenobi]

I say this with love. Toyota should be ashamed for ashamed for the s***ty transmission logic and the fart sounds the hybrid makes when the engine turns on. Other expensive suvs have zero problems with both of these things. X7 - perfect. GLS - perfect

Now I’m still buying my 700h because both of those other cars are pure people movers but still. Excusing Toyota is pure cope.

I think I’m going to fedex a respectful letter to the chief designer about these issues.