ECU Learning Myth

[Crawrolla]

Ok, this is obviously up for debate. I read several threads on here about disconnecting the negative on the battery to reset the ECU so it starts fresh and it will learn the "drivers" driving style. I've always heard about it and never put much thought to it since I disconnect my battery only when I deal with anything electronic (i.e. radio, headlights etc). When I install a hardware like turbo, exhaust and alike I don't even bother with the battery. So after thinking about it and looking up online, here is my conclusion;

The ECU does not learn the driving habit of the driver. When the ECU is resetted, it recalibrates the ignition and fuel based on the variables such as the fuel octane, ambient air temp and other sensors. This enables the ECU to calibrate the car the run efficiently and perform better based on the recalibration. So I don't think the driver's throttle push will be recorded as a driving preference. If I were to hop into my wifes car and she drives a lot more carefully than I do, that car will not be slower because she has been babying it. Thoughts?

[gold94corolla]

LOL... the ECU doesn't make your car faster or slower based on your driving habits, no

[Crawrolla]

Yes, that is what I'm saying. There seems to be this idea that resetting the ECU will make your car perform better and it learns your driving habbit. I don't think this is true.

[LeanBurn]

It doesn't make a lick of difference IMO.

[Overkill_311]

I am torn on this issue. I have heard the same debate for years! Of course neither side can provide concrete evidence to balance the scales in one direction or the other, HOWEVER I can tell you from personal experience that my car reacts to my driving style WAYYYYY differently than my wife's car reacts to my driving style.

Now, I dont know if this has anything to do with the ECU or not. What I do know is that BEFORE I added any modifications to my car it was still faster than my wife's.

When I drive my wife's car, it just seems "grannyish".

To put this to the test... I have decided to take the performance parts off my car, install them on my wife's car, and install her parts on my car. I will let you all know the results when I get done Sunday evening.

[xd_kidd]

The vvti adapts to persons driving style period. There's nothing to reset. It adapts after a good amounts of miles driven.. u won't increase power but slight gain in throttle response

[dwujcik]

Originally Posted by Crawrolla

Ok, this is obviously up for debate. I read several threads on here about disconnecting the negative on the battery to reset the ECU so it starts fresh and it will learn the "drivers" driving style. I've always heard about it and never put much thought to it since I disconnect my battery only when I deal with anything electronic (i.e. radio, headlights etc). When I install a hardware like turbo, exhaust and alike I don't even bother with the battery. So after thinking about it and looking up online, here is my conclusion;

The ECU does not learn the driving habit of the driver. When the ECU is resetted, it recalibrates the ignition and fuel based on the variables such as the fuel octane, ambient air temp and other sensors. This enables the ECU to calibrate the car the run efficiently and perform better based on the recalibration. So I don't think the driver's throttle push will be recorded as a driving preference. If I were to hop into my wifes car and she drives a lot more carefully than I do, that car will not be slower because she has been babying it. Thoughts?

Well speaking as a former master tech from toyota (now with Amtrak!!) There is a difference in re-learning the ECU. on our techstream software on the dealer scan tool there is an option to reset what the ecu has learned for Shift Points, fuel delivery and ect. Driving around town you will feel a difference between an 21 year old kid driving vs a 71 year old granny driving. the transmission learns how you drive and shifts accordingly. HOWEVER at 100% throttle the computer on both cars will react the same and there will be no performance change. hell it shuts off the ac when you go 100%.

So like i was saying around town driving you will feel a difference. but disconnecting the battery will NOT resent the memory. You have to have it reset at the dealer.

[Dimaoala]

Originally Posted by Overkill_311

HOWEVER I can tell you from personal experience that my car reacts to my driving style WAYYYYY differently than my wife's car reacts to my driving style.

Now, I dont know if this has anything to do with the ECU or not. What I do know is that BEFORE I added any modifications to my car it was still faster than my wife's.

When I drive my wife's car, it just seems "grannyish".

To put this to the test... I have decided to take the performance parts off my car, install them on my wife's car, and install her parts on my car. I will let you all know the results when I get done Sunday evening.

Don't both of you have 1.8 models? I think its just in your head... theres no way yours can be faster when both are stock lol. What are the transmissions for each?

[Overkill_311]

Originally Posted by Dimaoala

Don't both of you have 1.8 models? I think its just in your head... theres no way yours can be faster when both are stock lol. What are the transmissions for each?

They are both 1.8L models, both are automatic. I was half kidding when I wrote that. We raced once before I put on my intake and exhaust and I think the only reason I won is because she was too afraid to give it more gas. Swapping out the performance parts from my car to hers will allow me to see if the ECU/VVT-i/Transmission or whatever else remembers the way I drive or if it was the performance parts playing tricks with my mind. We shall see.

[Overkill_311]

After an exhausting day in the triple digit heat swapping out my parts onto my wife's car, and my wife's parts onto my car.... I am done.

So here is my analysis...

1.) My car with stock parts still feels peppy, but just doesn't have the "umph" that it did yesterday.

2.) I am aware that FULL control over the transmission and RPMs is impossible in an automatic transmission, however I have said it before and I guess I am saying it here again that SLIGHT control on shift points can be controlled with the accelerator pedal. I am not saying that I can hold 4200rpms in second gear.. that is redonkulous! I am saying that if I want to keep accelerating until I hit 5500 rpms instead of 3000, I can control that with my accelerator. Anyways - the point of all that is that my car with or without my performance parts "remembers" where I like to shift at.

3.) My wife's car feels alive. It is amazing to me how much reaction you get from simply adding CAI and exhaust. You can definitely feel the increase in HP and Torque.

4.) With all that said... and with the point made in #2... Her car with my performance parts... still does not shift where my car shifts. Driving the same way, on the same road. Her car seems to shift approximately 800-1000 rpms shy of where mine does when driving the same way in my car.


Now, I don't know if this helps anyone make any firmer decisions on the issue, but it makes me believe that something in the car (ECU, Transmission, ect) remembers the way I drive.

[BLUEMEANIE]

Originally Posted by Crawrolla

The ECU does not learn the driving habit of the driver. When the ECU is resetted, it recalibrates the ignition and fuel based on the variables such as the fuel octane, ambient air temp and other sensors. This enables the ECU to calibrate the car the run efficiently and perform better based on the recalibration. So I don't think the driver's throttle push will be recorded as a driving preference. If I were to hop into my wifes car and she drives a lot more carefully than I do, that car will not be slower because she has been babying it. Thoughts?

You are correct.

[PhatRoyale]

Seriously, don't kid yourself and think for a moment that it does. Because it doesn't.