Machine13

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.

Machine13

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?

Machine13

How do you put the gearbox in learn mode?

Cocal

I don't know about the ECU, but I suspect it does nothing for the transmission, but do know about the TCU, the latter upon reset has to re-learn the way you drive.

Machine13

Did you read that in any official Lexus documentation, website, brochures, tech bulletins, etc.?

Htony

When you say resetting ECU, by which means? Disconnecting battery or initializing ECU by grounding momemtarily grounding master clear line? If battery is disconnected
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.

rxtimes2

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.

Htony

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.

Cocal

I've had enough of this!! You keep believing what you want!

Machine13

rxtimes2 – I appreciate your responses. I’ve looked back on your posts in this thread and I think you and I seem to be in virtual agreement.

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.

Machine13

Some MB's apparently actually have adaptive transmissions. The reset procedure from sitting in the drivers seat appears to be for those models that have adaptive transmissions.

Htony

Of course MB always embrace leading technology leading the pack.. I notice you got a newer RX, why don't you try yourself?
Or dump the ECU software and look at it. Linux or C language based.

Machine13

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.

Machine13

I'm not sophisticated enough to dump the ECU software and scour through it. Doubt anyone here is. I'm under the impression it's encrypted anyway.

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?

BensonTT