Hesitation problem at various speeds (TSB info post #159)
#976
Pole Position
I am arguing that the transmission does not learn, per-se, not in any meaningful sense of the word learn. It obviously responds in real-time to real-time inputs from the driver and other various road conditions such as wheel slippage, etc., but nowhere does any official Lexus documentation say it learns the driver's style, and thus, records data values that can be deleted with an ECU reset.
#977
Pole Position
Lexus cars do not learn two driving profiles controlled by different key fobs. Lexus would state such an important feature in their marketing literature if it was a feature, wouldn't they? God forbid I used my wife's key and got in a crash because it upshifted too soon and I couldn't get across traffic. I'd think different key fob assignment would normally just be used for seat, mirror positioning and such. What if we both got in the car with our key fobs? How would the car know who's driving?
#979
Racer
No, I'm ultimately arguing that resetting the ECU does not change transmission behavior. This is the main point I'm trying to make. Do you agree or disagree with that statement, or don't really know for sure?
I am arguing that the transmission does not learn, per-se, not in any meaningful sense of the word learn. It obviously responds in real-time to real-time inputs from the driver and other various road conditions such as wheel slippage, etc., but nowhere does any official Lexus documentation say it learns the driver's style, and thus, records data values that can be deleted with an ECU reset.
I am arguing that the transmission does not learn, per-se, not in any meaningful sense of the word learn. It obviously responds in real-time to real-time inputs from the driver and other various road conditions such as wheel slippage, etc., but nowhere does any official Lexus documentation say it learns the driver's style, and thus, records data values that can be deleted with an ECU reset.
#980
Pole Position
#981
Lexus Champion
No, I'm ultimately arguing that resetting the ECU does not change transmission behavior. This is the main point I'm trying to make. Do you agree or disagree with that statement, or don't really know for sure?
I am arguing that the transmission does not learn, per-se, not in any meaningful sense of the word learn. It obviously responds in real-time to real-time inputs from the driver and other various road conditions such as wheel slippage, etc., but nowhere does any official Lexus documentation say it learns the driver's style, and thus, records data values that can be deleted with an ECU reset.
I am arguing that the transmission does not learn, per-se, not in any meaningful sense of the word learn. It obviously responds in real-time to real-time inputs from the driver and other various road conditions such as wheel slippage, etc., but nowhere does any official Lexus documentation say it learns the driver's style, and thus, records data values that can be deleted with an ECU reset.
TCU gets reset too. I wonder if you are thinking in terms of legacy older style gear box which is strictly mechanical. Most todays gear box is under the control of software
with some intelligence. If you have newer vehicle like 2016 RX or newer, try it your self.
#982
Intermediate
It is interesting to note that several folks have noticed a difference in shifting patterns after an ECU reset. The only way to really definitively answer the ECU reset effect, is to know how long the AI-SHIFT data remains in the computer. I have no idea, but experience with my two RX's seems to indicate that they shift differently from day to day (and the shifting in both sucks). I think the data is lost when the vehicle is turned off. ECU reset is done by disconnecting the battery.
Last edited by rxtimes2; 01-18-19 at 12:24 PM.
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Machine13 (01-18-19)
#983
Lexus Champion
Easiest way is to disconnect battery setting everything back to defalt on ECU and TCU?
Some other cars let driver perform some steps in the driver's seat like Benz cars it takes
~10 mins. Please remember today's tranny is electro mechanical box under software(firmware)
control in conjunction with ECU utilizing things like dog clutches, solenoids, sensor, etc.
Some other cars let driver perform some steps in the driver's seat like Benz cars it takes
~10 mins. Please remember today's tranny is electro mechanical box under software(firmware)
control in conjunction with ECU utilizing things like dog clutches, solenoids, sensor, etc.
#985
Pole Position
It is interesting to note that several folks have noticed a difference in shifting patterns after an ECU reset. The only way to really definitively answer the ECU reset effect, is to know how long the AI-SHIFT data remains in the computer. I have no idea, but experience with my two RX's seems to indicate that they shift differently from day to day (and the shifting in both sucks). I think the data is lost when the vehicle is turned off. ECU reset is done by disconnecting the battery.
I only question that the ECU or TCU saves any of this type of data at all, even if it’s until the vehicle is turned off. I don’t think the data would even need to be saved that long for AI-Shift to function the way Lexus describes it, in virtual real-time, using at most just the past few seconds’ worth of data. I know neither of us are saying we know the answer, but others are implying they know the answer but they are unable to provide anything other than what sounds like speculation.
#986
Pole Position
Easiest way is to disconnect battery setting everything back to defalt on ECU and TCU?
Some other cars let driver perform some steps in the driver's seat like Benz cars it takes
~10 mins. Please remember today's tranny is electro mechanical box under software(firmware)
control in conjunction with ECU utilizing things like dog clutches, solenoids, sensor, etc.
Some other cars let driver perform some steps in the driver's seat like Benz cars it takes
~10 mins. Please remember today's tranny is electro mechanical box under software(firmware)
control in conjunction with ECU utilizing things like dog clutches, solenoids, sensor, etc.
#987
Lexus Champion
Or dump the ECU software and look at it. Linux or C language based.
#988
Pole Position
You too. To be honest, I knew you'd break down trying to respond to that, because you can't actually provide any evidence, because whether you realize it or not, you're just providing conjecture. I was only looking for evidence, was that too much to ask for? Still no one has provided any. Sorry if it upset you.
#989
Pole Position
Any idea on if I did unplug the battery to reset the ECU/TCU how I would be able to tell whether any data that may or may not have been saved was deleted?
#990
Just got my car back from the dealer and I am 100% satisfied with this fix. My car doesn’t feel jerky and no hesitation on acceleration now.. The tech didn’t do the battery reset thing so I did lose the Sport Plus mode. Went back right away and they fixed it.. I did lose some of my car settings but not the radio presets. Car is a pleasure to drive now.
My dealer didn’t know anything about this TSB lol.. luckily I printed it out and showed them. This was done at Lexus of Royal Oak in Calgary..
My dealer didn’t know anything about this TSB lol.. luckily I printed it out and showed them. This was done at Lexus of Royal Oak in Calgary..
Last edited by BensonTT; 01-18-19 at 07:25 PM.