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The dealer most likely hasn't done the update correctly, most people on here say after the update the car drives better and is almost like being in Sports mode. I would suggest either they didn't do it OR they didn't disconnect power to the system to reboot it after the update which has happened to a few people. It's like some Microsoft updates, it gets loaded onto the car but needs a reboot to install.
Thank you for your reply. I am going to bring it back to the dealer and ask them redo the update.
Thank you for your reply. I am going to bring it back to the dealer and ask them redo the update.
Yes, don't let them fob you off, they can look and see which version of software is current on your car.
Just tell them straight that the update made no difference, ask to go for a drive with one of the techs and show then exactly what the issue is, could well be something entirely different that's causing the problem. These cars cost a lot of money, service from Lexus is supposedly on of the best, they should try hard to make you happy.
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Just because it exists on every unit does not mean it is not a mistake.
"Mistake" is not the same thing as "design decision". Mistake is subjective, depending on the values of the observer. Maybe the design decision WAS a mistake -- I wouldn't dispute that. I assume the design engineers had mpg targets to hit, from executive management, and they did what they had to do to hit the targets, using the transmission they were directed to use. I suspect the TSB backs off the worst of the shift-point algorithms -- probably compromising the fuel efficiency numbers in the process. My point is, they deliberately accepted the transmission hesitation in order to hit the required mpg targets. It wasn't an accidental or coincidental result -- it was a decision. IMHO.
If I am reading this correctly, you are saying that Lexus unintentionally created hesitation as a result of pursuing MPG gains, therefore it is not a fault and it's not broken? If it was unintentional, how could it not be a fault?
With the 450h, there is no hesitation at all and the 450h was geared toward fuel economy.
But the 450h cannot get out of it's own way😣 I had one as a loaner today. Uuuggghhhhhh
The hesitation, or “dead spot in the throttle”, is typical of most drive by wire systems. I installed a Pedal Commander in my 2019 RX 350L, and now there’s no hesitation under any condition. I’ve driven the RX450h, and though the CVT tranny was not for me, the hesitation wasn’t there. Trade offs, so pick your poison.
The hesitation, or “dead spot in the throttle”, is typical of most drive by wire systems. I installed a Pedal Commander in my 2019 RX 350L, and now there’s no hesitation under any condition. I’ve driven the RX450h, and though the CVT tranny was not for me, the hesitation wasn’t there. Trade offs, so pick your poison.
The hesitation being talked about is not like that, it's purely software mapping to get better fuel economy. The software changes up gear too soon so the car is in a higher gear more often which, in theory, results in better fuel economy. This means you come out of an intersection corner, the car has changed up gear already but you put your foot down and the car either doesn't accelerate hard enough or it abruptly changes back down a gear and than accelerates. When in Sports mode the car holds the gear longer so it's in a better gear coming out of the corner, keeps the revs higher and so, in theory, uses more fuel.
The updated software changes the mapping to be more like Sports mode and your gadget also changes the mapping software to be more like Sports mode.
The hesitation being talked about is not like that, it's purely software mapping to get better fuel economy. The software changes up gear too soon so the car is in a higher gear more often which, in theory, results in better fuel economy. This means you come out of an intersection corner, the car has changed up gear already but you put your foot down and the car either doesn't accelerate hard enough or it abruptly changes back down a gear and than accelerates. When in Sports mode the car holds the gear longer so it's in a better gear coming out of the corner, keeps the revs higher and so, in theory, uses more fuel.
The updated software changes the mapping to be more like Sports mode and your gadget also changes the mapping software to be more like Sports mode.
IT’S drive by wire, and drive by wire = software sending the signal to open the throttle body. My “ gadget “ fools the throttle sensor and opens the throttle body sooner. Simple. If we had a good old fashion purely mechanical throttle, throttle cable, and carburetor, we wouldn’t have the lame throttle response.
IT’S drive by wire, and drive by wire = software sending the signal to open the throttle body. My “ gadget “ fools the throttle sensor and opens the throttle body sooner. Simple. If we had a good old fashion purely mechanical throttle, throttle cable, and carburetor, we wouldn’t have the lame throttle .
Whatever you say mate.
I can put mine in Sport mode and there's no "lame" throttle response. Lexus have written software so there's no lame throttle response too. We are talking about different things.
The hesitation being talked about is not like that, it's purely software mapping to get better fuel economy. The software changes up gear too soon so the car is in a higher gear more often which, in theory, results in better fuel economy. This means you come out of an intersection corner, the car has changed up gear already but you put your foot down and the car either doesn't accelerate hard enough or it abruptly changes back down a gear and than accelerates. When in Sports mode the car holds the gear longer so it's in a better gear coming out of the corner, keeps the revs higher and so, in theory, uses more fuel.
The updated software changes the mapping to be more like Sports mode and your gadget also changes the mapping software to be more like Sports mode.
This plus the fact that manufacturers install 'Logic" in the programming, all to the worshiping of the higher MPG goddess. So once you give the input via the accelerator pedal the computer analyzes what you mean, was is a casual jab or do you really mean it, OK so you mean it now let me see how to achieve the task in the most fuel efficient way. This reasoning applies in the reg and even more so ECO mode and is thankfully absent in the sport mode. This is the result of government mandated fuel consumption MPG.
What if I like hesitation and rough transmission shifts? /s
Also before anyone complains about premium, no, the hybrid does not require premium gas. Most hybrid owners are not using premium with almost negligible impact to MPG (see hybrid forum). If anything, RX350 users are having to use premium to prevent hesitation issues.
Also modern engines prevent knock.
My 2016 450h hybrid does say to use premium fuel on the fuel door, however I actually get worse mpg with premium fuel that’s NOT Top Tier, vs. when I use Top Tier regular unleaded. There is a big difference in fuel mileage between the two. As a peace of mind measure, I had the dealer pull the engine history for the knock sensor to make sure I wasn’t causing any problems & everything was good. They told me that if I’m getting better mpg using Top Tier regular, to continue using it & I would be good. I don’t understand it, but it seems to be working. Ironically, I have noticed just a little better performance/mpg from Speedway & Shell branded gasolines. I don’t get the fuel mileage that the window sticker says I should, but it’s not horrible either. I can live with it, with some disappointment. No vehicle is perfect.
Folks let's keep this thread on topic please - it's for RX350 hesitation issues and associated TSB(s). There are plenty of other threads for MPG, octane rating etc. for both RX350 and 450H (in the hybrid subforum)
Update: I can't tell if the PowerTune Module is helping but I did uncover a fix for the hesitation in my 17' RX 350. I had disconnected my battery for 30 minutes and that would always fix the hesitation problem but only temporarily. I knew that the Sport mode fixed the hesitation problem so I gave the ECO mode a try knowing that this was all a software issue. I saved my driver settings in ECO mode (SPORT mode does not save) so I wouldn't have to always select it when I drove the car and have now driven the car for the past 3 weeks and the hesitation is gone! Problem solved for me!!
Update: I can't tell if the PowerTune Module is helping but I did uncover a fix for the hesitation in my 17' RX 350. I had disconnected my battery for 30 minutes and that would always fix the hesitation problem but only temporarily. I knew that the Sport mode fixed the hesitation problem so I gave the ECO mode a try knowing that this was all a software issue. I saved my driver settings in ECO mode (SPORT mode does not save) so I wouldn't have to always select it when I drove the car and have now driven the car for the past 3 weeks and the hesitation is gone! Problem solved for me!!
How did you save the settings in ECO mode? Can you walk us into that?
How did you save the settings in ECO mode? Can you walk us into that?
Once you put it in eco mode it remembers and starts the car in that mode. Just like when you select normal mode it also remembers that from last drive and will keep you in normal mode. Now sport mode is the only one that doesn't save once the vehicle is turned off.
12-11-20, 01:34 PM
