# Reseting ECU adaptation



## ed325i (Dec 20, 2001)

Hello,

As you know, the ECU in our cars adapt to our driving styles to achieve optimal fuel economy, but at a cost of engine performance and responsiveness. I read on e46fanatics some time ago, that we can reset the ECU's adaptation with the following steps:

325 / 330
1. Be sure that the car has been off for more than 3 minutes
2. Turn the key to On, but do not start the car. Leave it in On for exactly 10 seconds
3. Turn the key and leave it in Off for 10 seconds
4. Start the car

323 / 328
1. Turn the key to On, but do not start the car
2. Floor the throttle 4 times
3. Start the car.

The second procedure is more relevant to me, because I have a 328. I tried it today, and the car does seem to be more responsive afterward. First, would anyone verify these procedures? Second, can performing the 328 procedure flood the engine? Thanks.

Ed


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## Plaz (Dec 19, 2001)

Ed328Ci said:


> Leave it in On for exactly 10 seconds


Exactly how "exactly?" :rofl:

I've never heard this before.


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## ed325i (Dec 20, 2001)

Plaz said:


> Exactly how "exactly?" :rofl:
> 
> I've never heard this before.


That's why I am asking you guys.

Ed


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## eugeneDC/TX (Jan 14, 2002)

the first method was described in a few threads here. i did it and my throttle is more responsive. of course you could always go to the old, default unhook the battery method


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## Plaz (Dec 19, 2001)

Interesting. I'll have to try it.

I don't think you can "flood" a car with fuel injectors.


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## eugeneDC/TX (Jan 14, 2002)

i tried to do a search, half hearted attempt, but couldnt find the thread. nick 325xit 5spd i think is the one who mentioned it in the thread...


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## 31st330i (Jan 11, 2002)

So how does one clear the ECU (reset adaption)? Can't it be done by disconnecting the battery for a certain period of time?


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## Kaz (Dec 21, 2001)

31st330i said:


> So how does one clear the ECU (reset adaption)? Can't it be done by disconnecting the battery for a certain period of time?


Vince posted something a while ago stating that it must be done with some piece of equipment. Battery disconnect or keyswitch voodoo will NOT do it.


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## Alex Baumann (Dec 19, 2001)

Kaz said:


> Vince posted something a while ago stating that it must be done with some piece of equipment. Battery disconnect or keyswitch voodoo will NOT do it.


http://bimmerfest.com/forums/showthread.php?t=39418

Yup, the car must be connected to MODIC.


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## joema (Aug 28, 2002)

According to Steve Dinan, there is no e46 throttle adaptation in the sense most people think. It's true the ECU is constantly adjusting ignition timing, valve timing, and fuel/air ratio based on fluctuating inputs (throttle angle, gas octane, engine load, ambient temp, water temp, O2 sensor, etc). It does this to preserve engine thermodynamic safety margins while extracting maximum safe power. In essence the power available fluctuates somewhat because of these changes. Most people don't notice it, however to an enthsusiast in sync with his car, some days the car feels spirited and fast and other days sluggish. But this isn't because of learning type throttle adaptation based on driver input, it's because of ongoing adaptation due to engine thermal state and environmental conditions.

See also http://www.bimmerfest.com/forums/showpost.php?p=498913&postcount=6


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