DMPesso

Even after the update you still need to use sport mode? Maybe the update is different for f sport because mine feels much better to the point where I have not needed sport mode. Which RX do you guys have? If you look at the TSB there are different updates for f sport and AWD. The update almost feels like normal became closer to sport mode, just less sensitive. The throttle is too sensitive in sport mode for me.

xxx350L

I have run top tier Chevron 89 octane from day one, we don’t have 93 in So Cal, only 91 for premium. I’ll give it a try and see what happens. My car is a 2019 RX350L AWD, so my software is different because the shop foreman had to pick out the exact model to compare apples to apples in terms of factory loaded software with similar build dates. The test drive car had the very same drivability issues as mine, and because of that fact, I thought that Lexus was going to say, “ performing as designed.” This canned response is typical with a Ford. I did have to push him to do the TSB update, and the reason he resisted was because I did not use the term “bucking.” The TSB has specific “key” words in the description title; don’t describe the issue properly, and maybe get pushback. I called BS on the very subjective terminology, but argued that we are talking about the same thing or same driving issues. I digress, I will be on the road for a week traveling, so we’ll see how things go. Thanks for the fuel tip and your experience. Jesse J.

PWMDMD

Interestingly I just finished my first full tank of 87 octane fuel since having the TSB applied and I got significantly better mpg. Pre-TSB I averaged 19-20mpg and with this last tank I was at 23mpg. n=1 so who knows - I don't believe there was too much of a difference in highway vs town driving over this tank - I'll keep an eye on this over the next few tanks.

I'd be interesting if he TSB not only made the car more drivable but also increased efficiency....

ngstevee

took my 2017 rx350 f sport to dealer to have them look at hesitation and drone and shift slow .

- they reprogram the ECU .

car running great without any hesitation or drone noise.

DMPesso

I also have a 2017 F sport. Did they only do the TSB for hesitation and that took away your droning or did they do the exhaust TSB as well?

ngstevee

not sure which TSB they did,

but - car have zero hesitation and no drone noise.

Notes, I told the Service Adviser that all this is on normal drive mode,, not on sport or sport+ ,,

so none hesitation and drone noise on normal drive mode now.

llcw79

You should have TSB listed on the invoice. SB-0032-19 is for ECU reprogramming to resolve hesitation issue.

ngstevee

I do not see that TSB

GSFRX350

Looks like they did the TSB from 2017. As long as you're happy that's all that matters.

llcw79

Looks like they did it with old one(SB-0109-17, came out in Feb. 2017), honestly, I don't understand why they've applied old one instead of the latest...
Maybe contact dealer again? or someone here could answer why.. Sorry for not helping.

BensonTT

Anyone in Canada got the new TSB fix? Please

computerwi

From Techstream:

USA
L-SB-0032-19 (July 2, 2019)
Vehicle Bucking on 1 - 2 and/or 2 - 3 Upshifts and Surge Between 0 - 46 mph

Canada
TSB L-TCI-5285 (July 29, 2019)
Vehicle Bucking on 1 - 2 and/or 2 - 3 Upshifts and Surge Between 0 - 75 km/h

GRJFER

Recently bought a new RX350. Coming from a 2013 RX 350 I have noticed that throttle input is pretty stiff on the new 2019. Not sure this is associated with the hesitation people have mentioned, or an inherent design of the Gen 4 RX350's having just a little over 400 miles on it I can't say I've noticed any hesitation while driving. Are 19's coming with ECU flash, or is only upon request?

Eric0201

Did you apply the Canada TSB? I may ask dealer check this in next service.

gnguyen

My 2019 didn't come with the latest flash. They flashed it when I took it in for excessive drone&vibration and hesitation. None of their fixes worked.