ECU relearn

[Elise1204]

I know little about an 2005 OEM ECU relearn after reconnect the battery.

Think about 2 different ways to learn:

1. drive very aggressively for 500+mi or
2. drive normaly for 500+mi.

At the end, will the ECU be optimized for the very different driving style and stay the way it learned?

[charliex]

unplugging the battery doesn't do anything, urban legend, it is possible to damage the 'user area' of the ecu by disconnecting the battery at the wrong time, its a very specific window of time.

the ecu constantly adapts, but from fresh it has to make larger changes ( depending on the state of the engine/fuel/environment etc)

it has a two dimensional map that fills in for a range of RPM and load points, these all have to be visited for a period of time for it to make changes, intially or after something changed that effects things significantly, it'll make bigger changes, as time passes the changes get smaller and it gets closer to the target.

it does not 'lean' and stay that way, it always adapts, what you're looking for is that intial break in period where it trims things that are very different from stock so that everything is tickety boo.

it'll trim to your driving style, and happens fairly quickly, but just vary the load and rpm as it breaks in, beyond that just drive normally.

[Elise1204]

Originally Posted by charliex

it does not 'lean' and stay that way, it always adapts, what you're looking for is that intial break in period where it trims things that are very different from stock so that everything is tickety boo.

Thanks Charlie for your explanation.