Hesitation problem at various speeds (TSB info post #159)
#946
Racer
Thanks. I am so pissed at myself for not reading these insightful forum posts before buying my new RX. The same kind of hesitation complaints have shown up here for years. How Lexus can ignore the issue is beyond me. I have not had my first service yet and will ask for them to reset the ECU to see if that helps. Posts on here give mixed results about the value of that. I am staying with premium gas and driving in sport mode in the meantime.
#947
Pole Position
I don't have the hesitation, but I too use premium gas as the engine was designed with that in mind, also use the sport mode as it is more responsive. I think that these adaptive transmissions are the culprit and what makes it worse are dealers unwilling to spend the time to reset them properly. Dealers should be held more accountable by the manufacturers, all dealers and all manufacturers.
There is, of course, the ability to reset the throttle/fuel mapping by unplugging the battery for long enough. But that has to do with adapting the fuel delivery not an adaptive transmission.
I'm wondering if people are mistaking resetting their throttle/fuel mapping with resetting their transmission?
I'd love to see any evidence Lexus uses "adaptive" transmissions. I'm not talking about Lexus' smart transmissions that use automatic "AI" in real-time to enhance shifting based on driver's real-time throttle usage, because resetting won't do anything to change that AI behavior. But actual adaptive transmissions that store data that can be reset.
Last edited by Machine13; 01-17-19 at 12:12 PM.
#948
Racer
I'm legitimately curious. Have you read somewhere that RX 350's have adaptive transmissions? I've read other threads in this forum where people said that Lexus does not use adaptive transmissions and there is no such thing as resetting the transmission itself. Further, I cannot find anywhere on Lexus' website, brochures or in the owner's manual indicating they use adaptive transmissions.
There is, of course, the ability to reset the throttle/fuel mapping by unplugging the battery for long enough. But that has to do with adapting the fuel delivery not an adaptive transmission.
I'm wondering if people are mistaking resetting their throttle/fuel mapping with resetting their transmission?
I'd love to see any evidence Lexus uses "adaptive" transmissions. I'm not talking about Lexus' smart transmissions that use automatic "AI" in real-time to enhance shifting based on driver's real-time throttle usage, because resetting won't do anything to change that AI behavior. But actual adaptive transmissions that store data that can be reset.
There is, of course, the ability to reset the throttle/fuel mapping by unplugging the battery for long enough. But that has to do with adapting the fuel delivery not an adaptive transmission.
I'm wondering if people are mistaking resetting their throttle/fuel mapping with resetting their transmission?
I'd love to see any evidence Lexus uses "adaptive" transmissions. I'm not talking about Lexus' smart transmissions that use automatic "AI" in real-time to enhance shifting based on driver's real-time throttle usage, because resetting won't do anything to change that AI behavior. But actual adaptive transmissions that store data that can be reset.
#949
Driver School Candidate
I don't have the hesitation, but I too use premium gas as the engine was designed with that in mind, also use the sport mode as it is more responsive. I think that these adaptive transmissions are the culprit and what makes it worse are dealers unwilling to spend the time to reset them properly. Dealers should be held more accountable by the manufacturers, all dealers and all manufacturers.
See https://lexus2.custhelp.com/app/answ...xus-vehicle%3F
#950
Racer
Just as a point of clarification, the RX was not designed to use premium gas since 2011. They recommend regular gas with a minimum of 87 octane.
See https://lexus2.custhelp.com/app/answ...xus-vehicle%3F
See https://lexus2.custhelp.com/app/answ...xus-vehicle%3F
#951
Driver School Candidate
Hesitaion problem
Cocal, I really think a major issue could be that if the ECU uses driving characteristics based on the first thousand miles, it would be looking at break-in driving. No fast starts etc. I drove much differently then. Regarding most people not reading the owner;s manual, I simply think it is intimidating. It is by far the largest manual I have ever had from them, BMW or Mercedes. Not saying it is right but many find it easier to post on here to get answers.
#952
Driver School Candidate
I dont care to argue about this. It says what it says.
#953
Racer
Cocal, I really think a major issue could be that if the ECU uses driving characteristics based on the first thousand miles, it would be looking at break-in driving. No fast starts etc. I drove much differently then. Regarding most people not reading the owner;s manual, I simply think it is intimidating. It is by far the largest manual I have ever had from them, BMW or Mercedes. Not saying it is right but many find it easier to post on here to get answers.
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keneaise (01-17-19)
#954
Racer
Of course not. Can't believe you would ask such a question. I attached a link produced by Lexus just for information. It says: "recommended minimum octane rating for all 2000 through 2019 Lexus models". That means it should run satisfactory at that octane. I dont care to argue about this. It says what it says.
I see this as warning You OTOH sees it a recommendation I don't want to argue either
#955
Pole Position
I'd really appreciate it if you can you tell me what page it says this in your owner's manual, and which year owner's manual you see it in? Or maybe if you could possibly be mistaken?
I really think this is a technical mis-conception that is worth clearing up for people on this forum if at all possible. Because any mis-information can only cause confusion for others. Please can you provide solid evidence, not conjecture, such as pictures, links or page numbers that Lexus states their transmissions are adaptive transmissions or other similar wording?
Thank you for helping get to the bottom of this,
#956
This from page 685 of my owner's manual: Select octane rating 87 (Research Octane Number 91) or higher. Use of unleaded gasoline with an octane rating lower than 87 may result in engine knocking. Persistent knocking can lead to engine damage
I see this as warning You OTOH sees it a recommendation I don't want to argue either
I see this as warning You OTOH sees it a recommendation I don't want to argue either
#957
I just re-searched the entire 2019 owner's manual, all 777 pages, and nowhere does it say anything like "transmission learns your way of driving." In fact, the two words "transmission" and "learn" do not coincide in the same sentence anywhere in the owner's manual.
I'd really appreciate it if you can you tell me what page it says this in your owner's manual, and which year owner's manual you see it in? Or maybe if you could possibly be mistaken?
I really think this is a technical mis-conception that is worth clearing up for people on this forum if at all possible. Because any mis-information can only cause confusion for others. Please can you provide solid evidence, not conjecture, such as pictures, links or page numbers that Lexus states their transmissions are adaptive transmissions or other similar wording?
Thank you for helping get to the bottom of this,
I'd really appreciate it if you can you tell me what page it says this in your owner's manual, and which year owner's manual you see it in? Or maybe if you could possibly be mistaken?
I really think this is a technical mis-conception that is worth clearing up for people on this forum if at all possible. Because any mis-information can only cause confusion for others. Please can you provide solid evidence, not conjecture, such as pictures, links or page numbers that Lexus states their transmissions are adaptive transmissions or other similar wording?
Thank you for helping get to the bottom of this,
I too am under the belief that it is an adaptive transmission, my own experience with the car driving like a dog initially and then having the ECU reset by the dealer which fixed (mostly) my problem. I didn't mention the resetting to them only about the way it drove, they said when I collected the after the service then reset the ECU.
#958
Lexus Champion
Manual does not explain the complexity how it's proven 7 speed tranny works but shows how to reset(putting it to relearn mode) the box. It is done from driver's seat
with specific steps which takes about ~10 minutes. One can repeat the procedure multiple times to get the best out of it.. Then it'll learn your driving style(habits). I know
2015 Acura MDX had issues which made me to dump it. Lexus RX has same issues. But Audi 8 speed and BMW X5 8 speed, Benz 7 speed ones don't show this problem.
IMO, Lexus needs to improve it's software.
#959
Racer
I just re-searched the entire 2019 owner's manual, all 777 pages, and nowhere does it say anything like "transmission learns your way of driving." In fact, the two words "transmission" and "learn" do not coincide in the same sentence anywhere in the owner's manual.
I'd really appreciate it if you can you tell me what page it says this in your owner's manual, and which year owner's manual you see it in? Or maybe if you could possibly be mistaken?
I really think this is a technical mis-conception that is worth clearing up for people on this forum if at all possible. Because any mis-information can only cause confusion for others. Please can you provide solid evidence, not conjecture, such as pictures, links or page numbers that Lexus states their transmissions are adaptive transmissions or other similar wording?
Thank you for helping get to the bottom of this,
I'd really appreciate it if you can you tell me what page it says this in your owner's manual, and which year owner's manual you see it in? Or maybe if you could possibly be mistaken?
I really think this is a technical mis-conception that is worth clearing up for people on this forum if at all possible. Because any mis-information can only cause confusion for others. Please can you provide solid evidence, not conjecture, such as pictures, links or page numbers that Lexus states their transmissions are adaptive transmissions or other similar wording?
Thank you for helping get to the bottom of this,
P.S. Look also ate HTONY post just before this one where he too says that it's a learning transmission
Last edited by Cocal; 01-17-19 at 05:14 PM.
#960
Pole Position
This is just a suggestion. When it is safe, dry and the weather is good, try turning off the traction control(stability control) completely by holding the switch for three - five seconds(you will see two lights when the traction control is completely off). I have noticed that when doing this, our highlander and Camry feels much more flat in turns, responsive(steering feel is much more natural) and most importantly transmission behavior changes dramatically to being quick yet smooth in shifting (no hunting or hesitation). It also seems to make the car relearn ones driving behavior quickly. I urge some to try this and report back. Also after resetting the transmission, make sure to come to a complete stop before continuing, and don't feather the throttle too much when driving for the first 100 miles or so, this is what the tech told me after updating and resetting my Camry trans (it works).
Last edited by john341; 01-17-19 at 05:14 PM.
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Cocal (01-17-19)