When does the ECM switch from closed loop to open loop mode?

[strokerjlk]

Originally Posted by Paul Goodfield

Maybe we can get Steve Cole to weight in on this.

SOUNDS GOOD
what else have they got to do on new years eve LOL

[Paul Goodfield]

Originally Posted by strokerjlk

SOUNDS GOOD
what else have they got to do on new years eve LOL

Yea, lets all call him at once. lol
Well, maybe after the holidays unless he's as sick as us and reads it!

[ToBeFrank]

Originally Posted by strokerjlk

You can run in closed loop with a AFR of your choosing .
example: take it out of closed loop to say 13.4 and adjust ve to achieve 13.4 actual. Then when you take it back to closed loop by changing numbers to 14.6 it is actually running at 13.4 (+or - .5 according to what bias is set at) you have tricked the ecm and are now running in closed loop at 13.4 instead or 14.6.

No, that's wrong. If the cells you set at 13.4 are then changed back to 14.6, the closed loop will correct it back to whatever you have the CLB set to. It will run at 13.4 until the closed loop gets enough learning to correct it back. The closed loop cannot run at anything other than what the voltage from the O2 sensors tell it.

Note that the VE table will still have the VEs for the 13.4 target, but the ECM's "VE New" values will have it corrected back to the CLB target.

[BVBOB]

Originally Posted by ToBeFrank

No, that's wrong. If the cells you set at 13.4 are then changed back to 14.6, the closed loop will correct it back to whatever you have the CLB set to. It will run at 13.4 until the closed loop gets enough learning to correct it back. The closed loop cannot run at anything other than what the voltage from the O2 sensors tell it.

Note that the VE table will still have the VEs for the 13.4 target, but the ECM's "VE New" values will have it corrected back to the CLB target.

Good explanation, and also correct.

[Paul Goodfield]

Oh well,
t'was a nice thought though.

Did I fail to mention that I don't know what the hell I'm talking about?

or as my friends wife once told him "Just cause your right dosen't mean I have to agree with you!"
Paul

[HDMD88]

Originally Posted by BVBOB

Good explanation, and also correct.

Actually the end means is correct, it will fuel at the CLB setting once set at 14.6 but the explaination is incorrect. It won't have to learn from 13.4 to CLB setting....it should be there in a twinkle of an eye or with the click of a mouse, the VE doesn't have to change if it was synchornized to 13.4, it simply changes fuel value when you change AFR table.

[ToBeFrank]

Originally Posted by strokerjlk

take it out of closed loop to say 13.4 and adjust ve to achieve 13.4 actual (emphasis mine)

Originally Posted by HDMD88

Actually the end means is correct, it will fuel at the CLB setting once set at 14.6 but the explaination is incorrect. It won't have to learn from 13.4 to CLB setting....it should be there in a twinkle of an eye or with the click of a mouse, the VE doesn't have to change if it was synchornized to 13.4, it simply changes fuel value when you change AFR table.

Ah yes, doc is correct. That was my mistake.

[BVBOB]

Originally Posted by HDMD88

Actually the end means is correct, it will fuel at the CLB setting once set at 14.6 but the explaination is incorrect. It won't have to learn from 13.4 to CLB setting....it should be there in a twinkle of an eye or with the click of a mouse, the VE doesn't have to change if it was synchornized to 13.4, it simply changes fuel value when you change AFR table.

HMM, I thought that's what Frank said, lol

[AZFXSTB]

All I know is when it comes to what the ECM is doing, I'm in Frank's corner

Btw Frank, Happy Christmas and Merry New Year buddy

[AZFXSTB]

Originally Posted by GPO03FatBoy

Like TBF said, the only way to shift from 14.6 in closed loop is to alter the CLB. Altering VEs will affect open loop operation, but wherever the map is operating in closed loop the ECM will use the O2 sensor voltage to override other table parameters and self-correct to achieve the AFR set by the CLB value.

Doesn't the ECM take new values it learns to achive the requested AFR in closed loop and apply those delta's to the open loop cells as well??

Frank???

[strokerjlk]

Originally Posted by HDMD88

Actually the end means is correct, it will fuel at the CLB setting once set at 14.6 but the explaination is incorrect. It won't have to learn from 13.4 to CLB setting....it should be there in a twinkle of an eye or with the click of a mouse, the VE doesn't have to change if it was synchornized to 13.4, it simply changes fuel value when you change AFR table.

.

So then if you change AFR to 13.4 in the tables and adjust ve to achieve 13.4 actual then you can only run in open loop to maintain 13.4 actual ? This is what I have done in the past ran open loop only. But after reading this I arrived at the ( apparently wrong) previously posted conclusion
.
Tuning with Closed-Loop
Only calibrations that are closed-loop capable can be used for closed-loop operation. When a calibration is opened in Tuning Mode, a box in the upper right region of the screen will indicate if a calibration is intended for open or closed-loop operation.
The AFR table controls the operating conditions in which the ECM will enable closed-loop. The AFR cell must equal 14.6 for the ECM to enable closed-loop operation. This allows the user to control if and when the bike is in closed-loop simply using the AFR table.
For tuning of the VE tables, the recommended method has not changed. The AFR table should be set to 13.2 in all cells; this will put the bike into open-loop operation. The VE tables are then tuned to achieve the 13.2 in all conditions. Upon completion, the AFR table should be returned to its previous settings. This will return the bike to closed-loop operation.

.

The new table that has been added this year is the Closed-Loop Bias table. This table is used to shift the AFR richer or leaner during closed-loop operation. This table is a function of engine speed and map load. The cell values are the switching voltage that the ECM controls to. A lower voltage will control leaner, and a higher number controls richer. This table is used by the ECM in addition to the AFR table to determine what AFR to control to.
Example: Using calibration 141NX001. Looking at 1750 rpm and 40 kPa, the AFR table shows 14.6 and the Closed-Loop Bias table shows 447mV. With these values, the ECM will be in closed-loop operation and will control to approximately 14.4. In order to change the fuel delivered to the engine in this condition, the Closed-Loop Bias table would be used. 500 mV will make the mixture slightly richer, and 400 mV will make the mixture slightly leaner.
Changes to the Closed-Loop Bias table are done for the same reasons the AFR table would be changed: power, fuel economy, knock, etc..
.


So then the reason to take it to the 13.2 and tune ve tables to achieve 13.2 actual is so that when you take it back to 14.6 it is an actual 14.6 that it is self learning also?
.

Then I assume there is no way to run at the 13.2 that was adjusted with ve to achieve 13.2 actual and still be self learning? I though when you took it out of closed loop it didnt self learn to stay at 13.2 as the engine changes over time.
(Am I wrong again LOL) all the sudden I FEEL REAL DUMB
.
Or run anything else besides 14.6 - .5 (by adjusting CLB)? in closed loop?
.
I hope you are able to understand what I am saying and asking because I am not very good at conveying threw cyberspace!!
THANKS DOC, Bob,Frank
Always good to learn from those that in the know.
And I really want to learn this.
SORRY IF I MISLEAD SOMEONE!!!

[kslg]

Holy Crap, Doc's Back.

[HDMD88]

Originally Posted by AZFXSTB

Doesn't the ECM take new values it learns to achive the requested AFR in closed loop and apply those delta's to the open loop cells as well??

Frank???

Yes, in a manner of speaking, the ECM interpolates the learned data, meaning it takes an average of the learned cells and applies those changes to the open loop area too.....but if you take it out of closed loop the Adaptive Fuel Values are no longer being used and no learning is happening.
Don't take for granted that every cell changes in the open loop from the data learned....there are very few learning cells through out the complete map and the old MT6 files and SEST don't even use all the learning cells available, however, the MT7 files of the TTS MasterTune have set the learning cells in a smaller grouping in the map to be utilized where the bike runs the most and this is one reason the base (canned) maps are soooo much better than Harley's maps are.

[BVBOB]

Originally Posted by HDMD88

Yes, in a manner of speaking, the ECM interpolates the learned data, meaning it takes an average of the learned cells and applies those changes to the open loop area too.....but if you take it out of closed loop the Adaptive Fuel Values are no longer being used and no learning is happening.
Don't take for granted that every cell changes in the open loop from the data learned....there are very few learning cells through out the complete map and the old MT6 files and SEST don't even use all the learning cells available, however, the MT7 files of the TTS MasterTune have set the learning cells in a smaller grouping in the map to be utilized where the bike runs the most and this is one reason the base (canned) maps are soooo much better than Harley's maps are.

Doc, am I to assume the extra learning cells you are talking about is due to the extra TP columns in the TTS spreadsheets/tables?
Now for another question, if I read this correctly you state that the learned data from closed loop is applied over the entire map, even the open loop areas, do you feel this is the best way of handling fuel delivery, for example, in tuning, you would never make a change to the VE tables across the whole map to make a correction based on part of it, isn't this what is happening with this system using the o2 feedback?

[jcw]

I hope this question isn't too far out of place, but I noticed my performance 103" build was tuned entirely in open loop. No closed loop sections in the map anywhere (that i can notice). Im guessing thats ok??
Does that affect sensor life? If so, what happens when they go bad???