Can a gen III ECM "learn" ?

[BigGunZ]

Simply put... can a gen III ECM learn engine parameters? Common belief is that adding air through bolt-ons to a diesel, without adding fuel, only results in lower EGT's and maybe a slight economy boost. Reason I'm asking is that the changes that led to the gen III, were rooted in OBD II science. ie; electronics can change fuel delivery based on sensor input to maintain AFR's timing, etc. .



My experience is mainly with tuning OBD II gas engines and I'm new to electronic diesels... I would think that the smokers would need to compensate for certain parameters just like the gassers. Any thoughts?

 

[rbattelle]

I can't find anything in the powertrain diagnostics manual indicating whether the ECM has a learning procedure. That doesn't mean it doesn't, it just means Dodge didn't bother to discuss it. Cummins' manuals might indicate it, but I don't have the right one for that.



Personally, I suspect the ECM does have a learning curve, but it's probably not nearly as complex as what you'd find on a gasser. Remember that diesel's don't run to a constant AFR; they simply follow the fuel map (which I assume is a function of manifold pressure, throttle position, and RPM). Injection timing is accomplished via the crank position sensor (once the engine is running). Perhaps the only learn procedure the ECM follows is for the manifold pressure. I don't really know.



-Ryan

 

[JHMiller]

The EMC

I've notice what I though to be "an adjustable" curve with my 03. It actually feels like the Ecm adjust performance depending on the type of work the motor "has" been doing. I notice improved power "after" pulling my 5th for some time and a very noticable improvement say the nx day when not pulling. However, say the nx day, back to a dog. Dang Dime boys anyway!!

Or else I'm nuts, but I don't think so.

 

[CaptNemo]

Since the diesel doesn't need constant babysitting on air fuel ratio, like a gasser, the O2's, a true mass air and several other sensors are not used. Since alot of the ECM / PCM adaptive strategy is based on those sensors and A/F ratio and spark timing through the knock sensor, the need for a lot of adaptive isn't there. That being said, I'm sure there is a limited amount of "learning" the computer does but it's going to be pretty minor.