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-   -   ECM changed, now what? (https://www.team-bhp.com/forum/technical-stuff/100948-ecm-changed-now-what.html)

After a new ECM is installed is there any learning process involved for I 10 AT? Scorpio AT has this procedure and is done by ONLY experienced & trained personnel. This is just for info.

Spike

Isn't the ECM learning all the time? Why so much importance to the initial drive by experienced personnel? In fact, I should be the one doing it then. I doubt the Advaith AT expert has more experience driving ATs than me.:D

What kind of learning process? How is it carried out? For how many kms?

If it's done badly, can it affect the car average? I'm asking because my i10 AT gives an average of 6.

Can we re-teach the TCM?

All this assuming that TCM is behaving independently of the ECU.

We call it "Fast Adaptive learning", this has to be done every time the TCU / ECU is replaced, mapping done again, re-flashing etc. It is done by authorized personnel only with diagnostics attached.

Yes, possible. Something is seriously wrong with your car, usually the FE difference between a Manual and an Automatic is 10% variation, AT obviously being lower.

Yes, but not "WE" but @$$.

Yes.

Spike

Spike, why should they re-teach every ECU? Once you have the ideal data, can't you just load it onto every ECU?

Yes good question, they have to pair it due to a) the variations in manufacturing setup b) The ECU must recognize input from the other device as a genuine input. For e.g. even if the Engine and Map remains the same, the manufacturer has to pair the Injector codes with the new ECU so that variations due to the Injectors are not felt. This is referred to as Injector code flashing. The same logic applies with change of keys in Immobilizer etc.

Spike

Would not a reset (disconnecting battery terminal for 5-10mins) make the ECU start the learning process afresh ?

It is not variation in mfg setup..but because of a unique identity number of the unit..pls reconfirm.

if variation in mfg setup, it would be chaos sir..

^^ Sir, please explain unique identity number with an example? By variation I meant variation under tolerance bands.:)

Spike

Strangely enough I understood. :) Ok, not so strange because this topic has trespassed into my domain. Controlling devices using real-time OS is something I have done in the past.

Spike, I am still surprised that somebody has to drive each one to teach it to adjust to the tolerance band. I thought constantly self-learning ECMs have been around for a while. It is all about the intelligence of the learning module.

We often do heavy simulations during product design to see the actual field performance. We don't need to repeat it for every installation.

It would be way OT - The ECM would have a particular bit that handshakes with the particular device [Am not going into details here] - Only that needs to be done again - Entire reflashing would be a wasteful effort.

Hope you were able to follow.

Yeah, hence I asked you if this is applicable to Hyundai AT's as well.

I think I was not clear when I said flashing. When an Injector is changed, the whole flashing need not be repeated but the Injector pairing IS required, so is the Immobilizer pairing (if Immobilizer problem) and so on and yes there are manufacturing variations in Injectors as well.

OT- Is the Torque generated same for all 4 cylinders in a 4 cylinder CRDe / any other Engine? In other words, is the Frictional loss in all the cylinders same? Regarding why pairing of Injectors is required- answer to this question lies within my above question.

Spike:D

Its obvious that injector pairing is required..

Also I don't know torque variations in each cylinder~ can you explain how and why there are variations. How they are balanced etc?

supremeBaleno, a reset will only clear the temperory memory of the ECU like trip, time, DTE cliberation, may be error codes etc..

I believe spike here is taking about the EEPROM memory of the ECU, which only dealers can write?. So that each one is tuned specifically to its master car.

Spike, can you confirm?

Yes, but why?

I thought you must be knowing all these, anyways here it is:-

There are 2 prime reasons why Torque variations / fluctuations occur in an Engine:- a) Engine variation (variation in Mechanical systems, Friction, Imbalance of Pistons, Slap etc.) b) Fuel system variation (Specially Injectors) which results in "Surge" or "Spike" :D.

First, we will analyze why it happens, then we will move on to how to control them. Basic fundas first.:). OK here is a pic of the T- Theta (Torque Vs Crank angle) of a Heavy duty Diesel Engine.



What does it convey? (This is a controlled version but still useful for understanding).

Mechanical Engineers does it ring any bells (Flywheels - Mechanics of Machinery)?

Yes, I am talking about the errors which only the dealer / person having the correct diagnostic tool can correct.

Spike