Ok,so I've spent the past couple of days trying to look through the literally hundreds of posts but didnt really find an answer. Can anyone with an FSport that has had the TSB done, confirm weather or not the TSB made a significant difference in Sport+ mode as well? I recently had a 2019 BASE model loaner and that thing had waaaaay better throttle response in Normal mode than mine has in Sport mode!

 

Our 2018 RX 350 AWD also experiences hesitation but only when engine is cold and only when turning right or left from a stop. When making a 90 degree left or right turn when engine is cold, the engine hesitates a split second before taking off. Have tried premium, mid grade and regular gas and various different brands the past year but problem still exists. However, if engine is warmed up, the hesitation seems to have disappeared. Our RX is set to "ECO" mode. Haven't tried the "NORMAL" mode to see whether hesitation still persists.

 

I haven't had a TSB done but as per the manual Sport and Sport+ have the same software mapping so throttle response should be the same. Sport+ only adds in a firmer suspension and more weighting to the steering.

 

If you think this 8-speed sucks go try the 9-speed in the MDX. While I agree the RX transmission isn’t perfect it’s miles ahead of the ZF 9-speed used by Honda/Acura in shift smoothness.

 

I can't imagine driving around in ECO all the time! You've got to try at least Normal. I use Sport most of the time while driving around town and Normal the rest of the time. Never ECO as I see no advantage in it at all. Just have to remember that when shutting off the engine, it will revert to either ECO or Normal when restarting, depending on what it was set at. If shutting off while in Sport, it will revert only to Normal at restart. In other words you have to select Sport each time you start the car. Try Sport a few times and see what happens.

 

After I saw your message I drove the RX for a few blocks with SPORT setting. Hesitation when making turns seems to have disappeared. I tried to put it in NORMAL mode by pushing the round **** but screen won't confirm the NORMAL mode selection whereas when in ECO or SPORT mode, screen will confirm the specific mode. How do I know when the RX is in NORMAL mode if the screen nor the left hand side of the instrumental panel won't confirm the mode it is in? Also, is ECO green light supposed to come on (left side of instrument panel) when vehicle is in NORMAL or SPORT mode? Thanks.

 

The normal position has no special confirmation only the useless eco and the sport have it.

 

My guess is that eco mode only exists for the vehicle to meet some government fuel economy standard and is not intended to be used after you drive off the lot.

 

Yes, I've seen some improvement with this issue when disconnecting the battery. On another note, for what it's worth, we just got a 2019 RXL and the transmission seems to be much better compared to the 2016.

 

Got mine done yesterday. 17 FSport. HUGE difference! They did not disconnect the battery so I lost Sport+ and customized modes at first. I still immediately felt a dramatic difference from before the update. After I disconnected the battery, I dont think there was any difference in the way the trans was behaving. The code is different from what is in the TSB, so that may or may not be why it wasn't WORSE before resetting as others have posted. And to answer my own question, Sport mode is definitely improved after the update! Also, I had bad experiences at my dealership in the past, so I didnt even want to waste my time with this for the past 2 years. BUT, either I got lucky or this dealership greatly improved their customer service! If you're getting brushed off and not getting the results you want, ask for a different service writer and/or technician. At my particular dealership, I learned that the "advanced" techs are at an offsite location. The first bad experiences I had, the tech claimed my bumper gap was normal and there was no such thing as lexus personalized settings!? Even though it's in the owners manual!! This was probably because this was one of the onsite techs that only does oil changes and tire rotations all day! Sorry for the long post but I hope it helps someone! Oh , and print out the TSBs and take them with you. It provides solid proof that there is a known issue. I got 4 done and I feel like I'm driving a brand new car!!

 

Can you elaborate what you got done or post a picture of the service report they handed you? Could help out a lot of people on here, including me. Thanks!

 

Thanks to the forum posters who reported on the repair bulletin on this fix. After reading the posts--after buying a 3 year old RX 350 AWD---I was worried that I made a big mistake. The salesman and service manager said they were not aware of this ECU transmission reset. I downloaded and emailed the bulletin--Thanks again!--and brought in the car one day after the sale. I emphasized that the battery needed to be detached after the patch was downloaded to reset the ECU module properly.

And the reset worked. For what it's worth they said that the driving history sensed by the ECU ffom the prior owner would be erased, which was exactly what I wanted. The transmission does still search for the right gear more that my prior 6 speed transmission did, but the low end hesitation is gone. The difference is very noticeable and performance has improved nicely. Buyer's remorse is now eliminated.

 

Im sure this has been mentioned here plenty of times but it is insane to me lexus would recommend using regular gas in the same engine that always asked for premium, JUST to make the car appeal to soccer moms and the usual people who want buy the RX that wouldn’t buy it if they knew it required premium. It’s like a different car with 93 vs regular gas. Just in case anyone is having the hesitation or sluggish pedal response. Put some good 93 in there and you’ll feel the difference!

 

I believe fuel economy is a big thing for you guys in the US, I'm in Australia and even though our fuel is around US$6.00 a US Gallon we don't worry as much. We have 3 tiers of fuel, Standard Unleaded 91, Premium 95 and Premium 98, the RX here has the recommended fuel as Premium 95. If I use the Standard Unleaded 91 the hesitation is worst for sure, the 95 helps a lot, still there a little sometimes but acceptable. If I'm driving in a lot of traffic where the hesitation becomes annoying
I put it in Sport mode and she's sweet again.

 

I love how the standard is 91. When I was in Germany they had the highest quality gas. 87 octane was unheard of. I can’t believe $6 a gallon is what you pay, how much does it cost to fill the car up? I’ll never put less then 93 in the car again