"re-training" The Ecu

[Sluggo]

I read on the PlanetSoarer site about how the ECU 'learns" the owner's preferred driving style and adjusts to that style. They describe how to force the ECU to re-learn by pulling the fuse that powers the ECU. Well, I did it, and I'm very happy with how it worked out. My automatic now shifts later, harder, and actually does a fair amount of engine braking. It also gets to wide-open throttle operation much faster. Feels like a different car.

It kind of makes sense. When you first take delivery of your new SC, you're told not to accelerate hard and keep the revs low. The ECU learns this and thinks this how you drive.

[bean_8044]

Trust me, unless you keep on it 24/7 itll go back to "normal" in a few days

[bartkat]

Trust me, unless you keep on it 24/7 itll go back to "normal" in a few days

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I don't think it has any effect when parked. :D

However if you continue a somewhat "get on it" driving style, or just hit it once in awhile, the car will still stay adjusted to that. Of course, if you go to a grann style, it will adjust to that too.

Also, if a car fails emissions tests, resetting the ECU to default can often adjust enough to pass the test.

[tg8tor]

Where is the fuse to the ECU?

[DobieG]

Does this work for any type Lexus? I drive an ES that was previously driven by a elderly man who never went on the freeways. He only drove 13k miles in 5 years.

How does one know which fuse powers the ECU?

[Sluggo]

The ECU is on a circuit fused by the green 10 Amp fuse which is third from the top. If you open up your fusebox and look inside the lid, there is a key to what fuse controls what. (fine print, be warned).

Warm up the car fully (the procedure won't work if the car is cold) and park it somewhere where you can safely do some hard starts to 30-40 mph. Turn it off, open the fusebox, and remove the ECU fuse. Wait a minute or two, then put the fuse back in.

When you start the car it may idle rough for a bit. No matter, just do 4-5 hard starts and stops with the overdrive off ... really trounce it. You don't need to go much faster than 35 or so (I didn't, anyway). Congratulations, you're done. :)

I don't know if it works on ES models, but I suppose it's worth a try. I can't see it hurting anything. You're on your own finding the ECU fuse, though :(

[Neo]

It is a great little fix but you will have to do this periodically. I don't think you can dive it hard all the time since you cannot control the traffic and other drivers. ;)

[Lex3486]

So I assume this applies to the SC3 too? Cause I noticed all you guys have SC4's....

[sircpeedy300]

So I assume this applies to the SC3 too?  Cause I noticed all you guys have SC4's....

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I also wonder about the 300. Doubt it changes much of anything in a 5 speed though.

[Sluggo]

Pulling the green fuse resets the engine ECU. The ECU for the auto transmission is on a different circuit. I'm not sure how effective resetting the engine ECU will be on a 300, but I would think whatever it does wouldn't depend on transmission type.