What is the proper procedure for ECU adaptation?

[airjawed]

I was wondering what the proper way to get the ECU to adjust fuel trims and run through its emission self tests is.

How do you go about it after changes in tune or fixing/clearing codes or in my case putting in a new battery?

My thoughts:

1) Cold engine
2) Clear codes
3) Throttle body adaption(either vagcom or wait for ECU to do it)
4) Start car and let warm up a few minutes
5) Drive slow speeds(25mph) with moderate accelerator positions for about 10 minutes
6) Get on highway and drive moderate for about 10 minutes...no WOT
7) Back to surface roads for 10 minutes
8) Park car and remove ignition for a few minutes
9) Check vagcom blocks such as LTFT, rpm/load barriers, boost control and of course codes.
10) See what readiness codes are not set and then set those.... as seen in Bentley or Ross Tech site(generating/setting readiness).

I'm specifically interested because I had codes for cat efficiency emissions and overboost when I generated readiness without doing a drive cycle. On another occasion I cleared codes and then did a drive cycle followed by generating specific readiness and then no codes. Or maybe the other way around....I forget.

My logic is that the ECU should first adapt some of the engine management like fuel trim and boost control and then check on the emissions side. Getting the sequence right would also be important for tuning. Would love feedback from you guys on this.

[rockcandy]

Adjusting fuel trims is done through very light, steady throttle at highway speeds (though maybe it called for 55, don't remember.) Do this for several miles until it goes steady. This is after clearing codes btw.

[airjawed]

I just came back from a test drive.

The first time I cleared codes and went for a drive cycle...unfortunately this made my cat code come back immediately. Didn't bother with trying to set readiness.

The second time I cleared the codes but set readiness first followed by a drive cycle... when done this way I did not get any codes. I'll have to remember this when it is time for my cars inspection.

How do dyno tuners do it? Are tuners setting readiness and then drive cyling on the dyno for tune revisions?

[airjawed]

Adjusting fuel trims is done through very light, steady throttle at highway speeds (though maybe it called for 55, don't remember.) Do this for several miles until it goes steady. This is after clearing codes btw.

Thanks...maybe just have block 032 up and put it into cruise control until the multiplicative shows something steady.

[hodrosS42001]

Thanks...maybe just have block 032 up and put it into cruise control until the multiplicative shows something steady.

what cat codes are you getting.. I have the same problem

[airjawed]

what cat codes are you getting.. I have the same problem

Sometimes I get a cat code...cat efficiency below threshold on bank 2. But there has also been a time when it didn't show up at all. Makes me wonder how the ECU determines codes and how it goes about adapting might play a part in performance/emissions. Probably an issue only because the one cat is older. With a completely sorted out car it may not really even matter how you go about it. I never get that code on bank 1(replaced cat 1 year ago).

Does our ECU go into sleep mode ever? Is there a way to tell? Some cars give you a hint by having radio light blinking or window lock light going out.

[airjawed]

Well...cat code came back doing the setting readiness process as well. It is cold out today so my cat is probably not warming up much compared to other days. Most likely cat is bad.

Still wondering though what is the proper procedure for getting ECU totally adapted.

[phila_dot]

Still wondering though what is the proper procedure for getting ECU totally adapted.

What does this mean?

There's no such thing as totally adapted, the point of adaptation...it continuously adapts.

I'm genuinely trying to figure out what you're looking for here.

[britishturbo]

I just flash and go. *shrugs*

[Monty23]

I think the OP is referring to ECU emission readiness for state emissions testing....

[2.7taudi]

For readiness, you want to drive it slow and easy. My car wouldnt pass evap and catalyst readiness because i drove it hard as hell. Next day, i drove it easy barely hitting 2.5k and it passed all the readiness. I ran to the inspection station before any codes came back. BTW if you car is newer than 2000 you can have only 1 NOT READY and still pass. If its older than 00 2 not ready are allowed.

[airjawed]

What does this mean?

There's no such thing as totally adapted, the point of adaptation...it continuously adapts.

I'm genuinely trying to figure out what you're looking for here.

I guess I'm talking about how to go from cleared codes to a state of continuous adaptation. Is there an ideal way?

It takes a while for Fuel trims(multiplicative) to show something other than zero, the additive happens pretty quick. I also see zeros for Boost control block 111(I think) for a while. Not sure if those are suppose to show zeros but they usually change to something after many drive cycles.

In my mind the ECU has some things it continuous adjusts to but there are some things related to hardware that get adapted to only during certain times.

Put it this way:I can set readiness and then take car for a drive but there will still be some blocks with zeros. Makes me think there is more to it than start and go. I've actually gotten best driveability when I didn't get on it all at once. When I've slowly increased the aggressiveness over days the car has behaved better...less surging and better shifting(tiptronic).

[airjawed]

I've looked in Bentley and didn't find a procedure for what to do after battery replacement...maybe this would be the best place for the info.

[phila_dot]

Every single adaptation has it's own conditions under which learning occurs and some of them are then only applied under specific conditions. There is now way to generally summarize all of the ECU's adaptations.

Generally, adaptation reveals something that is operating outside of optimal.

You are saying that after resetting the ECU, your car doesn't perform as well until after getting somes miles in and apparently adapting somewhere?

There's really no way to speed this up, especially if you haven't narrowed down exactly where the actual problem is.