Off-topic but you are using your heavy duty cooling system whether you realize it or not.

 

While driving the freeway this morning, I attempted to accelerate into the fast lane and the throttle DID NOT RESPOND! I was traveling at about 65 mph, and as I pressed the go pedal, I got absolutely nothing. It was as though someone had cut the link between accelerator and the engine...no revs, just idle. The car behind me was approaching fast and here I am putting my foot to the floor several times hoping to pick up a lower gear and get out of the way. The delay finally gave way to slow acceleration, and had the guy behind me not recognized that I was actually slowing down, I would have been hit. This issue is deadly serious and the car is going into Lexus tomorrow morning. I sincerely hope that a fault code was generated; waiting for it to happen again could prove fatal. I had a throttle position sensor fail on one of our other cars (Hyundai Sonata), and it was just like that; no rpm’s above idle. I’m only at 2,500 miles on this 2019 RX 350L, so needless to say, I’ve lost a lot of confidence in the safe operation of this car. In my opinion at this time...it’s not safe. Period.

 

Have you done the new 0032-19 TSB? I’ve had that happen before if I’m merging and I press the gas too hard out of nowhere. Haven’t really noticed this after the TSB

 

I have not had the 0032-19 TSB done yet, but the total loss of power today will be addressed tomorrow at the dealer. I will push for the TSB software update and hope that it resolves most of the transmission issues. Did you ever experience a total loss of power on acceleration? This is just unacceptable, not to mention, dangerous. I’ll let you know the outcome.

 

Yea, before the TSB it would happen every once a while. It was dangerous to the point I only drove the car in sport mode, as I didn’t feel safe. Sport mode keeps the car in a lower gear so it never happened in sport. It was most noticeable when driving gently and suddenly mash the pedal to pass or merge the car hesitated for 1-2 seconds before it downshifts then lunges you forward. Honestly I hated the way the car drove before the TSB, constant hesitation, always had to drive in sport mode. Knock on wood after the latest TSB I haven’t noticed it happening again and have no desire to use sport mode anymore. The car is much more responsive and stays in a lower gear similar to sport mode. Make them do the L-SB-0032-19 TSB and don’t take no for an answer. The actual TSB is posted on this thread if they give you any issues you can show them

 

Today, I send my vehicle for 8000KM service in Canada, the service manager said they do not have any ECU update after 17 model.
I am not sure if they have 0032-19 in Canada.

 

I had that happen once....full-throttled acceleration onto highway and at about 3500rpm the car stopped accelerating, the tach bobbed up and down around 3500rpms for 4-5 seconds and then it started accelerating normally again.

 

4-5 seconds! That’s unacceptable. Let me know if you have this problem after the latest TSB.

 

That is not one bit true. Show them the TSB someone uploaded it to this thread. It covers ALL 2016-2019. The car is built in Canada what a shame they don’t know better

 

I has not happened since having the TSB applied. The vehicle drives night and day since the TSB (in a good way).

 

Yup I agree. Night and day difference. Was starting to hate the car before the TSB.

 

Today I had the TSB done, took some convincing on my part, but they agreed to flash it. It’s definitely an improvement, especially on a long incline (no hunting), but at a low speed rolling type stop, and then upon acceleration it is still hesitating and requires putting the pedal to the floor to pull out of it. The new shift strategy seems to hold each gear a little longer, and that really improves mid range performance. There is, in my opinion, room for a lot of improvement on the low end. Thank you DMPesso, and others, for your informative responses.

 

Glad to hear it helped. For me the biggest difference was the low rpm power. I had to press the gas a lot harder before. Now the car is much more responsive on low rpms. If you want even more improvement try a tank of top tier 93 gas. I notice a big difference when I have 93 vs 87 in the car.

 

I drove 45 miles home from the dealership yesterday in “normal” mode, no sport mode as I wanted experience the full effect of the update. Today I’ll take it out and see how “sport” mode performs around town. Before the update, I was using sport mode all the time and, in sport mode, would not experience the slow speed lag or hesitation when rounding a corner then accelerating out of the corner...that’s the condition that’s still an issue. My guess is that sport mode will correct that. Maybe the procedure will be: sport mode around town and normal mode on the freeway since it did not hunt at all on the freeway yesterday. I don’t know how many software updates there have been thus far with this 8 speed, but I don’t think this is the last. Again, thank you for your help and have a safe weekend, Jesse J.

 

I put mine in Sport mode all the time and I use 93 gas. Haven't noticed any significant change in gas mileage from Normal in either local or highway driving. Wish there was a way to make Sport the default, but apparently there isn't.