I have been logging these paramiters on A-tap to come up with this Cell Break Down

LTRIM's
MAP
RPM
FTC's
TPS
Vehicle Speed (Just to know what gear I'm in)


I have been given this link from another board but it does not give enough specifics. http://smiley.tzo.com/fbody/atap/atap_ftc.htm


I'm trying to come up with a detailed cell break down to help people tune individual cells. If anyone has logs that show the cells I don't have details on, please let me know what is putting you in those cells. I would like to try and mimic the situation.

 

The above link is very dated. Most of the info below the guys on this board put together within the past 10 months. No flames here..... just fact....we're very lucky that the gurus contribute


FTC # 0 - 15 -> see VE table in the Fuel Trim and VE thread Here -->Fuel Trim and VE

(FTCs # 3, 7, 11, 12, 13, 14, 15 and 22 are PE cells)

FTC #16 - idle - park AC on

FTC #17 - idle - park AC off

FTC #18 - idle - in gear AC on

FTC #19 - idle - in gear AC off

( FTCs #16, 17, 18, and 19 are closed loop)

FTC #20 - idle -open loop

FTC #21 - deceleration

FTC #22 - WOT

***This should help you out with most of it. Good Luck.

joel

 

This may explain what you are looking for:
http://www.efilive.com/upload/efiliv...ltft_cells.gif

Regards
Paul

 

Paul, I disagree with that. For example:

Cell 4 in my car is good up to 2599rpm between 9-17.1kpa per A-tap. Then at 2600 rpm it moves to cell 5 between 9-17.1kpa.

From 17.1-23kpa under 2599 it is in cell 8, above 2600 rpm 17.1-23kpa it is in cell 9.



According to your post cell 4 would be under 899rpm and so would 8 and 12.

Why do I see those cells all the way up to 2599 rpm? Then I see 5/9/13 2600+ and above? If you look at my findings vrs yours, they are completely different. Now I have heard A-tap does not reflect KPA properly which I could understand having some impact with my data. Does it show the correct FTC when loging?

 

Those values look too low for MAP, are you logging kPa or inHg for MAP?
The breakdowns for MAP using inHg are these:
00..10.92
10.93..16.82
16.83..22.73
22.74+
That's pretty close to what you've got in your spreadsheet.

The rpms look too high - sure you're logging the right data?

Try this: In first gear, down a long gentle sloping road, open the throttle so that the MAP is fairly constant in the middle of one of the MAP ranges - use the brake to allow the RPM to go from 800 to 3000.
Stop the car, stop the log and take a look, you should see the 4 cells for that MAP range and the cells should change at the following rpm boundaries:
900 1400 2200 give or take 100rpm (for hysteresis)

Disclaimer: Don't watch the screen while you're driving - it will soon be against the law in CA.
http://www.itsa.org/resources.nsf/Fi...-chaptered.pdf



Regards
Paul

 

Paul,
I'll have to get the car out soon. Home sick with the flu right now

Car is a 2001 M6. Using the DOS version of A-tap. As far as what I am loging:

LTRIM's
MAP
RPM
FTC's
TPS
Vehicle Speed

I'll try and post one of my logs later today. I'll highlight the transitioning cells that I am talking about from 2599-2600 rpm (4 to 5, 8 to 9, 12 to 13)..

BTW your disclaimer made me laugh.

 

I mapped these out a long time ago, I had stray cells hits all over the place but the majority agree with Paul.

Fwiw, 22 is the only PE cell.

 

Eric - No flames here, I'm trying to understand differences.
It's been quite awhile since I was logging closed loop data.

My understanding of PE/WOT ( and God knows I've been wrong lots of times...hell, I'm the "King of OOPs").......

PE

1.) MAP to enable is 15 kPa. All PE fueling is Open Loop.

2.) Fueling is determined by the PE/RPM and PE/Temp tables. Table values are additive, and taken together, they are "multipliers". Basically they are reciprocals of 1. Example: 1/PE-RPM and 1/PE-RPM + PE-Temp. Multiply the reciprocal values times Stoich = 14.7 : 1.
At 5200 RPM PE-RPM value = 1.2277, 80*c PE-Temp = 0.00 so target AFR = 14.7 *1/1.2277= 11.97
3.) Cells 3, 7, 11, 12, 13, 14, & 15 are PE cells. All have MAPs greater than 15 kPa. PE can occur within each cell - without transitioning to cell 22. Therefore , these PE cells are able to function both open and closed loop.
Scanning "fuel mode" allows us to see them function Open Loop and Closed Loop.

WOT

1.) Hot and Cold tables - Hot enable Temp shown - *C. Below this enable temp we're working off the Cold Table. Both Hot and Cold have TP% vs RPM to enable WOT.

2.) WOT is a Subset of PE consisting of Cell 22 - only. When TPS% exceeds a given percent , at the tabled RPM, cell 22 references the PE table(s) for fueling. If any of the PE Cells 3, 7, 11, 12, 13, 14, 15 are referenced and the WOT- TPS%/RPM values are exceeded - then Cell 22 is referenced and the PE table is used as target fueling.

For Both PE and WOT MAP hysteresis is 5 kPa.

All of the above is Closed Loop functioning with proper enable temp and O2 sensors.

Open Loop full time - no O2 sensors and closed loop disabled. Cell 22 is Part Throttle and WOT. Cell 22 references F/A table for PT fuel target until the PE MAP, TPS% and RPM are met. At enable MAP and TPS%/RPM (WOT Tables) the PE tables are referenced. So cell 22 is not referencing the PE/WOT table 100% of the time when running Full time Open Loop. Cell 22 references the F/A Multiplier Table for part throttle.


How can Cell 22 be the only PE Cell???



"KingofOOPs" formerly known as BinksZ06

joel

 

Here is a log from the begining of December. 12/4 FTC Log

The first Excel sheet shows the data in time. This will show you a timed event as it was recorded. I highlighted groupings of cells as I saw them 4,8,12,0 and 5,9,13,1.

The second excel sheet is broken down by the cell groups then sorted by MAP. As you will see these follow suit to what I have in my cell break down list.

As you can see I am really only seeing cells 4,8,12,0 under 2600 RPM and 5,9,13,1 over 2600 RPM. As well as 4/5 below 17.1 MAP, 8/9 between 17.1-23 KPA, 12/13 between 23-28.9.

The only thing that changed slightly is some cells are slightly off in regards to RPM and MAP. This is due to the timing of the log (A-tap being slow).

 

My 2000 Z28 seems to be the same. If you had efilive, you could see that table that was posted by them. On my car, it only uses two rpm ranges, < 2500 and > 2500 IIRC, so I see results like you do.

 

My car is always in closed loop for cells 0-15, and always open loop for cell 22. I live in a mountainous area where it is easy to get the car to go into cell 22 (PE mode) when it isnt even close to WOT.

If you consider it a PE cell because MAP is greater than 15kpa than ALL cells are PE cells by that definition.

Just to be clear, there is no evidence to suggest that cells 0-15 are used in open loop.

 

LIL LS1: What are you driving? Do you know the PCM operating system number?
You can find out all your PCM calibration numbers if you have a 99+ car. If you have a 97/98 car then it is a little "different".

Download EFILive (http://www.efilive.com/downloads) and connect using your Atap cable, you should be able to see that info on the [OBDII (F7)] tab page [PCM] sub page.
The quickest way to send me the info about your PCM is to connect, then press Ctrl+G and save the error report from the [Report] tab page and send it to me (paul at efilive dot com).

This may be a case of a cell table that we have not seen yet. I do recall someone on this forum or another saying that some vehicles differ - but we have not seen one yet. Maybe we have now.

Regards
Paul

 

Paul,

I will try and download it and send you the info tonight.. It is a 2001 M6 Camaro.

Here is a recent PCM flash file from edit. Will that help? Edit File

 

Hi LIL_SS,

As your invetigation has shown it does appear that your Camaro does have different cell boundaries.

We will modify EFILive in the next patch release to display them correctly.

Thanks for bringing it to our attention.

Regards
Paul

P.S. I have sent you an email about the "work" you did to figure out the cell boundaries.

 

Your welcome Paul. Glad I could help others like myself..

 

Thanks Eric!
joel

 

huh? I was hoping you'd retort and prove me wrong.

 

Nope.......give me a few days.
joel

 

IMHO,

Once ECT meets the temp (122 to 140 degrees) it switches to closed loop and stays there. It cannot go back to open loop unless the ECT goes below the switch temp or something wrong.

PE or WOT are not in open loop, its in one of the 7 modes PCM has and that is PE MODE.
Open loop also would use AIR which does not happen in PE.
It is not just 15 KPA, its a "AND" along with other requirements to go into PE mode such as TPS angle
WOT is not just when in cell 22, as per EPA/SAE its when engine is at 100% engine load so cell 15 is just as well WOT and cell 22 is PE if for that engine what load the cell operates in depending on also what the RPM is and what the MAP value is.

 

Yes, I understand that PE is not the same as open loop. I should have stated that.

My opinion is that the pcm always operates in cell 22 when in PE mode. I also noticed that when going to this cell it updates the barometer value, even when the absolute pressure is not ambient and the throttle is not 100%.

Somewhat related to this is that I no longer monitor the fuel system status. Simply looking at the cell number gives me more information about what's going on.

We need to organize a public and coordinated effort to reverse engineer and flowchart the pcm code, or we'll still be unsure of how our changes really affect its operation for years to come.