jimby

I keep reading on this forum that the ECU in the scooby will somehow learn a new setting???

as far as im aware the ecu does what its told by the chipset, this reads inputs from sensors (crank position, air flow, air temp, lambda, throttle position, knock, boost etc) and it instructs the fuel injestion and ignition systems to do operate according to set rules (the map).

so what the hell are people on about?? resetting an ECU will not reprogram the map to make the engine act differently as nothing has changed. when the ECU see a different sensor input it will act accordingly immediately and not over some 'learning period'


well?

ru'

So the ECU detects knocking caused by bad fuel. It changes the timing/fueling whatever to accomodate this (lowering performance).


But, it never re-adjusts so from then on the car is poor.

Or, the next ignition cycle it goes back to what it 'should be' and knocks again, thereby damaging the engine over time.

Either way, bad behaviour.

Or, it slowly changes back ('learns') over time.

I haven't taken the ECU apart or checked the srouce code etc., but I believe this is normal - it'd be the kind of thing I'd build into an ECU for a performance car.

Gridlock Mikey

'Sall gone quiet over here You can't go posting info like that which rocks the very foundation of the "..... Dare I ever drive my car" brigade They will all have to go and totally re think their approach to how scoobs work and some folk might even loose some business because the notion that the ECU learns, actually fuels some of the myths about how engines blow up, thus the whole "Monitor mentality" fraternity will be deeply distressed by your comments

Seriously though, I wouldn't know if an ECU "learns" or simply "adapts" like you say, to varying inputs from various sensors.
I suppose it must be able to adapt, lets say you run 97RON Fuel and then stick 98 RON & Booster in. In order to take advantage of the fuel, the ecu "adapts" if you then stick 97 in again, it would, I presume, "adapt" back.

If however, one of the sensors is deteriorating, i.e it can't suddenly start working again, then the ECU would remember the state of that sensor and it's readings or put another way "learn"

By resetting the ECU, the way I see it, you are telling the ecu to forget what it has "learnt" and pretend all is well again. Fine if you have just replaced the failing sensor, but if you are resetting and not changing anything, then surely that is a bad thing?

Anyway, just my take on a subject, i'll fack orf now back to muppets

Seeya

Graz

You obviously haven't discovered our technical forums yet and the search function ....

Yes there are base maps and these don't change. There are however correction tables that contiually adjusted by the ECU according to the readings it gets from various sensors, the knock sensor being a prime example. If detected the ECU will apply increasing amounts of of correction to the ignition map to retard it until the knock hopefully goes away, obviously you want to keep this info stored for the next time you start up the car.

On some of the older models once retarded it took a long time before the ignition was advanced again. An ECU reset cleared all the correction tables, and the ECU would know this so goes through an initialisation routine (the learning period) so you start again from the base maps, initially with a fair bit of retard dialled in I would guess, and then applying fresh correction according to the onset of knock. This wouldn't happen until the cars has been running for a while as it would need to reach operating temperatures first before sensible sensor readings can be obtained.

The newer models, I would guess, after a pre-determined time period would try reducing the ignition retard until knock is again seen and the wind it back a step or two. Therefore once whatever problem was causing the knock (e.g. duff tank of fuel) has gone away the ignition correction table would return to normal values.

Graz

To add...

It doesn't "learn" in an artificially intelligent way if that's what your thinking

When we say learn it just means that it's using various algorithms to analyse sensor inputs and adjust the correction tables accordingly.

Gridlock Mikey

So there

shaunywrx

DevilHimSelf

Put another way
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R T F M !

scoobyboy

just going on a different ecu take the new legacy 5spd auto transmission ecu if you change the oil you have to reset the ecu because it learns the way you drive and monitors the state of the oil and adjusts pressures accordingly so that you still get the same smooth gear change at 30k that you did when it was new. you put new oil in and it confuses it so you have to restart the learning all over again

tath