M8 - Set Lambda during a CL to OL transient

[hdmanillac]

Set Lambda (white) is the signal from the ECM
SL (red) is calculated Set Lambda based on AFR table
LF (green) is calculated Lambda for the front cylinder
Ping F (yellow) is calculated based on Spark Knock Front signal.

My question is the following: Why on M8 motors Set Lambda seems to be freezed during Closed Loop to Open Loop transcients ? It was not the case on TC motors.

[hrdtail78]

What is the difference between set lambda (white) and calculated set lambda based of AFR table (red)? 

[hdmanillac]

The white trace corresponds to the ECM signal and comes from the DPV log.

The red trace is a calculated field in MegaLogViewer that is supposed to follow the AFR table (SL=AFR(MAP;RPM)).

I don't understand why the ECM signal Set Lamda is not following the AFR table during transcients betwin CL and OL.

[rigidthumper]

Correlated with the knock retard activity? The ECM has a subroutine to enrich the AFR outside of the map during knock events.

[hdmanillac]

No, the knock retard is not my first concern. But maybe there is a link with this observed phenomena.

This phenomena exists even without knock retard.

[hrdtail78]

In some cases that take a bike out of closed loop.  It isn't based on target anymore.  Acceleration enrichment table for example is a pulse width adder based on VE table.  PE mode over rides main AFR target if it is set richer.  During these times.  The ECM doesn't care about AFR main target table and since it isn't using it.  Might not show it accurate in the data.

Does the data allow you to see when acell is active or when PE mode is active?

[hdmanillac]

The DPV no longer records AE DE signals in the logs for M8. And for PE the DPV never recorded it neither on M8 or TC.

Even if the ECM doesn't care about AFR table during some transcients, Set Lambda (the signal) is normally not affected by AE DE and PE. Set Lambda is normally taken directly from the AFR table.

[Jamie Long]

The DPV no longer records AE DE signals in the logs for M8. And for PE the DPV never recorded it neither on M8 or TC.

AE/DE are not native channels on the Harley M8 databus

Set Lambda is normally taken directly from the AFR table.

Set Lambda is derived from the value in the AFR/Lambda table + other lookup tables & multipliers (PE, component protection, warmup enrichment, etc..)

[hrdtail78]

My bad.  I am use to TTS, and it shows accel and decel with the m8's.

[Jamie Long]

My bad.  I am use to TTS, and it shows accel and decel with the m8's.

As far as I recall AE/DE are not active PID's in Centurion, DTT, ect.. on M8 models either (at least on 2017-2020 bikes).
Just curious how its expressed in the software you're using, are you able to view these as channels or on/off bit? 

[hrdtail78]

You cannot view this attachment.In histogram it has also shown as AC DE not being green when activated.  With TC's it was bit in the upper right corn of main screen of Data Master. Same as it showed kick stand placement.  In later m8's.  It will show as a trace at the bottom in bits, and in the list but it needs to be pulled up in one of the blank data channel spots.  Both will come under the same on both places.   

[Jamie Long]

In histogram it has also shown as AC DE not being green when activated.  With TC's it was bit in the upper right corn of main screen of Data Master. Same as it showed kick stand placement.  In later m8's.  It will show as a trace at the bottom in bits, and in the list but it needs to be pulled up in one of the blank data channel spots.  Both will come under the same on both places.   

Understood, thx

[Jamie Long]

The white trace corresponds to the ECM signal and comes from the DPV log.

The red trace is a calculated field in MegaLogViewer that is supposed to follow the AFR table (SL=AFR(MAP;RPM)).

I don't understand why the ECM signal Set Lamda is not following the AFR table during transcients betwin CL and OL.

If you created a calculated field in MLV software and it does not follow Set Lambda the ECM is commanding, your calculations are leaving out a piece of the equation and missing one or more factors mentioned in my earlier post

[hdmanillac]

Ok. I suspected there were some hidden parameters influencing Set Lambda.

But then how to explain that we did not observe that on a TC?

[hrdtail78]

Set Lambda is derived from the value in the AFR/Lambda table + other lookup tables & multipliers (PE, component protection, warmup enrichment, etc..)

This is what I thought also.  The data coming out of the ECM is already calculated with the other tables. Set lambda, desired, targeted lambda.  How ever it is labeled. 

With this.  Sometimes programs will just repeat last known data if it hasn't gotten new data to refresh it.  This can clearly be seen by opening logs in basic excel file.  Not saying this is bad.  Just what it is.  Do we really need to update eng temp 25 times a second?  If you look at o2 readings.   With a controller that records at a quarter speed of the data recording device.  The options are to repeat data or show no data. 

[Jamie Long]

Ok. I suspected there were some hidden parameters influencing Set Lambda.

But then how to explain that we did not observe that on a TC?

You answered your own question; if the calculated fields you created in MLV software matched the ECM's Set AFR/Lambda in one example but not another the factors were correct in one equation but not the other. Without having the data in front of us I don't know specifically what we are working with, however the lookup tables vary (many times greatly) by calibration level and vehicle model. For example an M8 bike with a 824/921 calibration has very different lookup tables than an early AFR based 176 calibration. 

The Set AFR/Lambda channel on the data bus is reporting the net result, post process; it goes like this:
What should the ECM command? = programming (calibration lookup tables)
What did the ECM command? = ECM data stream - Set AFR/Lambda
 

[hdmanillac]

An other input:

if the bike is equipped with a target tune kit, it works in a closed loop practically everywhere on the AFR table and we do not observe this "Set Lambda" gel phenome during the cruising / acceleration transients.

[Jamie Long]

An other input:

if the bike is equipped with a target tune kit, it works in a closed loop practically everywhere on the AFR table and we do not observe this "Set Lambda" gel phenome during the cruising / acceleration transients.

Same rules as noted earlier apply with Target Tune

[hrdtail78]

An other input:

if the bike is equipped with a target tune kit, it works in a closed loop practically everywhere on the AFR table and we do not observe this "Set Lambda" gel phenome during the cruising / acceleration transients.

Something that has never been answered to my satisfaction.

An other input:

if the bike is equipped with a target tune kit, it works in a closed loop practically everywhere on the AFR table and we do not observe this "Set Lambda" gel phenome during the cruising / acceleration transients.

Same rules as noted earlier apply with Target Tune

This is something that has never been laid out and answered to my satisfaction.  It's advertised as 100% closed loop for 100% of the table.  Yet, same rules apply to TT as apply to limited narrow band closed loop areas.  There are adder tables that kick you out of closed loop.  PE mode being one of them.  With PE mode in later cals controlling more and more of the riding area.  How does it all play along.  My best understanding is TT has influence over the fuel trim tables.  These trim tables have influence over VE tables.  Having these trim tables active while adding the PE enrichment into the mix.  Would only skew the VE tables away from the target table.  So, how can the ECM stay in closed loop mode and activate PE mode at same time?

Seems it would be best to turn off the adder tables that we can, and shut off PE mode while using TT feedback and just worry about mapping VE's to airflow and then reactivate these tables once we are satisfied with VE mapping.  I mentioned this to DJ's tech line and was told it figures it out.  I asked how and was told it just does.

This industry is lucky in the fact that we have some good tools that already filter a lot of this data out for us.  This is how MyTunes, Vtune, Smart Tune, auto tune basic and pro all work.  I think this is what MLV and programs like it exist.  (not necessary for this industry) They take raw data and allow you to filter out any other tables and only worry about steady state while mapping VE's.  BUT since we do not have full access to all tables and all data fields with all the programs.  Sometimes it is easier to just use the programs created for what we have.

[Jamie Long]

Target Tune calibration operate differently than standard tunes from several different standpoints; they operate 0-5v O2 inputs (rather than 0-1V), the O2's are interpreted differently related to O2 control such learn & freeze rate, and some definitions are used (or ignored altogether) differently between the different sets of O2's & hardware. The overall closed loop scheme with Target Tune is really basically the same as with the OEM narrowbands with some key differences; TT uses closed loop over the entire AF/Lambda table regardless of Lambda value; closed loop will follow any commanded AF value in the calibration as long as the command is within the range the sensor can measure (.70-1.15 Lambda/ 10.5-17.0 AFR). Closed loop is active during PE and even under DE, we filter decel out using min MAP threshold so it doesn't try to follow & learn what's happening during transients. You can also use CL during warmup enrichment once the sensors are heated (25 seconds or so). TT uses CLI (short term) and AFF (long term – stored) fuel trims, what the ECM learns in short term is eventually stored in eprom and will resume at key on, the calibration also controls the amount of rich/lean fuel correction that can be learned, as much a +/- 40 %.

I couldn't agree more on the helpfulness of the various tuning programs & utilites. Like others my craft has evolved greatly over the years as the bikes, hardware, and toolsets evolve.

[hdmanillac]

I would like to understand why Set Lambda is stuck at 0.981 in an area of the AFR table where it should be lower.

Here is my AFR table


Here is Set Lambda from a log


At 2250 rpm, PE mode is off. And even if you disable AE DE in the cal, you still have this strange Set Lambda freeze.

This suggests that the AFR table is probably locked in the map, even if we can change the values.

[Jamie Long]

I would like to understand why Set Lambda is stuck at 0.981 in an area of the AFR table where it should be lower.

At 2250 rpm, PE mode is off. And even if you disable AE DE in the cal, you still have this strange Set Lambda freeze.

This suggests that the AFR table is probably locked in the map, even if we can change the values.

Its difficult to speculate without seeing all of the data and the calibration. Lambda is not stuck or locked, what you're likely seeing is the histogram you created in MLV is rounding the data in the columns, and remember the ECM interpolates the lambda command from a cluster of cells not a single value; for example look in the 20Kpa column in your histogram, it's .969-.980 when the lambda table is .960   

[hrdtail78]

I would like to understand why Set Lambda is stuck at 0.981 in an area of the AFR table where it should be lower.

Here is my AFR table


Here is Set Lambda from a log


At 2250 rpm, PE mode is off. And even if you disable AE DE in the cal, you still have this strange Set Lambda freeze.

This suggests that the AFR table is probably locked in the map, even if we can change the values.

That is something I haven't seen.  Looking at the cell at 2250 and 90 KPA.  The target desire is way leaner than any cell around it.  I would suspect to see something from a value of .920 to .880.  Most tables that will activate in this area would be an adder table that would add fuel.  I can't think of any table that would influence the target to be leaner in this area.  The ECM is going to always go to the richer target, but PE mode is turned off anyway.

If you are emailing cals:  cnsspeedshop@hotmail.com  I'd like to take a look.

[hdmanillac]

hrdtail78, you have put the finger on ! I sent you an email.

 

[hrdtail78]

hrdtail78, you have put the finger on ! I sent you an email.

 

My tuning laptop with MLV is at the house.  With the histogram feature I can get a better time stamp of when you were in that area and correlate that with the raw data in the excel file.

I'd make sure what type of filters you have going in MLV and I don't know if you are street or dyno tuning and weather is like.  BUT one thing I would try.  Set your entire target to 13.2.  Turn off PE, AE/DE and collect some data.  This will take care of tables we have control over and get the interpolations of cells out of the equation.