AutoVE Tuning

[VetPet]

I've been doing some AutoVE tuning (finally) and am close to getting all the BEN's around 1. My C5 is a 2001 and has the 5 pin connector that includes IAT sensor as well. With the MAF disabled per the instructions, I was wondering if I should be concerned about whether the MAF is really disabled or not? I've read that the only way to know for sure that the MAF is disabled is to remove the connector but if I do that then I have to find another way to connect the IAT sensor. Is this really necessary or can I be reasonably assured that the MAF is fully disabled by changing the parameters as shown in the AutoVE tutorial? I did check for the DTC's for the MAF and they were there and the MIL did not illuminate.

Thanks,
:cheers:

[joecar]

If you get any of the DTCs P0101, P0102, P0103 then the PCM has failed over to VE table only mode (SD mode).

The AutoVE Tune procedure has you disable the MIL for those DTC's.

[SSpdDmon]

To make sure the MAF fails, I swap the high frequency with the low and the low with the high. Then, I change the fail limits to 1 so that the first time the MAF fails, the DTCs Joe mentioned are set.

[VetPet]

Thanks Gents. I did get the PO codes mentioned so I feel pretty sure that I'm in SD mode. Gotta make another run for some more data that should get by BEN's to around 1 and then I'll start logging the LTFT's. After that I'll be recalibrating my MAF. Is there any reason to tune the rest of the VE table above 4000rpm if I'm keeping my MAF?

:cheers:

[joecar]

I found that on the street, as hard as I try, I can only hit certain parts of the VE table (including lower RPM (< 4000) and upper MAP/RPM (>90/>4000) corner too)...

This means it's very unlikely for me to hit the "unhit" regions of the VE table, so rather than thrash my transmission, I called it good, and when I have time I'll rent some dyno time, or buy my own dyno shop... ;)

[VetPet]

Buy the dyno shop......it works out cheaper in the long run. :muahaha:

:cheers:

[Garry]

Buy the dyno shop......it works out cheaper in the long run. :muahaha:

What if you can't find a dyno anywhere close? :nixweiss:

:lol:

[joecar]

Get a business loan, lease a suitable building in a light industrial zone, lease/buy a dyno and other equipment, do paid advertising, and tune you own car while waiting for your first customer... may have to do other things in the mean time to make ends meet (rebuild engines, trannies, axles...)...

Easier said then done, but certainly doable.

[Garry]

:lol: Not really my line of expertise ... ;)

[VetPet]

As Jimmy J.J. Walker used to say "Dyno.......mite"! Think two treadmills will work.......one for each wheel?

:rockon: :cheers:

[TAQuickness]

lmao...

Garry - Hill's and heal-toe. I can hit most every spot, and I don't worry about the rest.

[redhardsupra]

I can hit most every spot
is that what she said?

[VetPet]

Hill's and heal-toe.

Never tried the heal-toe method. Not sure if the missus would like it. Have you tried the mistle-toe method. Works great under trees but not good on hills.

:D

[VetPet]

On a more serious note. After having completed getting my BEN's real close I transferred the VE calibrations to my original tune and set about disabling the MAF and going out to log my LTFT's to see how they looked. I added the two PID's for LTFT and started logging data. The problem is, I can't get any readings. My LTFT's are showing zero. I know the LTFT's are enabled in my tune as I checked the parameter. Since this was my original tune and the only things I changed were the VE table values,spark low octane table & disabling of the MAF why am I not getting any LTFT readings?

:help2:

[joecar]

Vet,

Did you enable B3801 and reduce the temp on B4205...?

Joe

[VetPet]

B3801 is enabled and B4205 is where it was before. B4206 is disabled also (use 02 with open loop table). Should this be enabled?

:cheers:

[VetPet]

B3801 is enabled and B4205 is where it was before. B4206 is disabled also (use 02 with open loop table). Should this be enabled?

:cheers:

Is it possible that the 02's are just not working and that's why I'm not getting any LTFT readings? When you disable the LTFT does this shut down power to the 02's or is it just that the voltage is not reported back to the PCM?

:master:

[joecar]

When you disable LTFT's, the O2's are still powered (my LC-1 is powered this way)...

the PCM just ignores the O2 voltage output, and assumes the value of zero for the LTFT's.

[dc_justin]

When you disable LTFT's, the O2's are still powered (my LC-1 is powered this way)...

the PCM just ignores the O2 voltage output, and assumes the value of zero for the LTFT's.

O2s aren't ignored with LTFT's disabled, just long term learning is disabled. O2's are still used for short term fueling, aka closed loop operation, assuming his enablers allow that to happen. :cheers:

[joecar]

Justin, yes you're right, just the learning is disabled. I think he has both long term and short term learning diabled also.

Time to get more coffee....

:cheers:

[VetPet]

I did disable the LTFT relearn but not the STFT during my AutoVE tuning. Just to be sure I had enabled the LTFT I downloaded the tune from my car and checked the LTFT setting and it was enabled. I've gone back over every parameter that was changed and then put back to where it was originally and can't find anything wrong. My head's about to burst. :bash: :help2:

[dc_justin]

I did disable the LTFT relearn but not the STFT during my AutoVE tuning. Just to be sure I had enabled the LTFT I downloaded the tune from my car and checked the LTFT setting and it was enabled. I've gone back over every parameter that was changed and then put back to where it was originally and can't find anything wrong. My head's about to burst. :bash: :help2:

When AutoVE tuning, you should have all closed loop operation disabled. Meaning, no STFTs.

[VetPet]

According to the AutoVE tuning document, you only need to disable the LTFT's. With LTFT's disabled, changes in STFT's that would normally update the LTFT's don't have any effect so there shouldn't be any need to disable the STFT's as well. This is my understanding of the theory and I could be wrong. In any case, I've enabled the LTFT's and don't see and data when I'm logging in either the data tab or the LTFT maps. My monitored WB02 AFR is very close to what's being commanded so I could assume that the LTFT's are pretty good but I'd like to get the actual data. Something here doesn't make sense.

:cheers:

[VetPet]

I just want to add one thing. My battery was drained because I left my DC to AC converter turned on and plugged into the power supply in the car. This would be the same as disconnecting the battery which means that the LTFT's the PCM had learned would be wiped out and it would have to relearn them again. I did one more data logging session after I got the car started before I put the PCM into closed loop, speed density. Is it possible that the reason I didn't see any data is because the car needs to be driven again for a while before I'll see any LTFT data? Just a thought but I thought I'd throw it out there.

Thanks,
:beer:

[TAQuickness]

Setting B4205 to maximum should disable your closed loop.

[Blacky]

I just want to add one thing. My battery was drained because I left my DC to AC converter turned on and plugged into the power supply in the car. This would be the same as disconnecting the battery which means that the LTFT's the PCM had learned would be wiped out and it would have to relearn them again. I did one more data logging session after I got the car started before I put the PCM into closed loop, speed density. Is it possible that the reason I didn't see any data is because the car needs to be driven again for a while before I'll see any LTFT data? Just a thought but I thought I'd throw it out there.

Thanks,
:beer:

The fuel trims learn very quickly. For example, if your LTFT for a particular cell was say 10%. That 10% would appear back in the LTFT cell after about 1 or 2 minutes of driving in that cell under the correct conditions.

What most people mean when they say something like "the LTFTs take 100 miles or more to learn" is that it takes 100 miles or more to hit every cell for at least long enough for the PCM to learn the correct trim.

Just rambling here...
Basically the learning process goes like this:

PCM sees O2 sensor voltage is too far fromthe crossover point (defined by {B4105}) for too long (defined by {B4113}).

So it adjusts the STFT by {B4111} or {B4112} to bring the O2 sensor voltage back towards the crossover point {B4105}.

After the STFT correction has reached its limit {B4115} and {B4116} the LTFT is updated and the STFT is reset back to 0. You can observe this happening if you clear the LTFT and then log STFT and LTFT. (Only if your VE table is far enough out to require significant trim changes).

The LTFT cells are updated from the LTFT value using the filter in {B4106}.

The process is very efficient at getting the fuel delivery accurate and remembering it and continually adjusting it over time as conditions change and components deteriorate.

Regards
Paul

[TAQuickness]

^^^^ wow. never seen it spelled out like that before. Almost makes me want to try CL again.

[VetPet]

Appreciate the detailed information regarding STFT/LTFT's. The issue is still why I can't get any LTFT data after enabling LTFT learning again. The MAF is disabled as outlined in the AutoVE tutorial and I added the LTFT Pids. As I watch the data tab LTFT Pids and the LTFT Maps the data is always at zero. No LTFT data is showing up at all and I've driven for quite a while. Are my values possibly in an out of bounds range that don't show up and is this even possible? "I think I'm not in Kansas anymore Toto"

This is going to drive me to :beer: .

[Blacky]

Log the PID {SAE.FUELSYS} which will tell you whether the PCM is in closed loop or open loop. If it is in open loop the LTFT will not be updated (i.e. no learning).

Also try logging {GM.SSTATE05} it also contains some intersting bit fields to do with fuel status:


Description Status=0 Status=1
Decel Fuel Cutoff Inactive Active
This start Warm Cold
Fuel Trim Learn Disabled Enabled
Heated O2S Bank 2 Sensor 2 Not Ready Ready
Heated O2S Bank 2 Sensor 1 Not Ready Ready
Heated O2S Bank 1 Sensor 2 Not Ready Ready
Heated O2S Bank 1 Sensor 1 Not Ready Ready
Fuel Loop Status Open Closed

[VetPet]

Blacky, Added the pids suggested and monitored data. SAE.FuelSys shows it to be in closed loop. GMState05 pid also shows fuel loop system = closed, fuel trim learn = enabled, decel fuel cutoff = inactive. I reloaded my original tune prior to doing any VE tuning and was able to get average LTFT and just LTFT's. Also logged the 02 sensor voltage to see if they were working which they were. Loaded the AutoVE tune back up and tried to log LTFT's again but no values once again. Also getting no values for STFT's. I checked to make sure I had enabled both the LTFT & STFT's again and they were. I can't make heads nor tails out of this. Sounds like something from the X files.

:wtf1: pardon my french. :)

[TAQuickness]

What are you settings for:
{B3605}
{B3801}
{B4205}

[VetPet]

What are you settings for:
{B3605}
{B3801}
{B4205}

I don't know how to paste images of my tables for you to see. Tried to do a copy and paste but won't work. B3801 is enabled. Thanks. :cheers:

[Doc]

With the screen shot you desire to capture on screen, hit the "Print Screen" button and open a photo editor, MS Publisher, Paint, etc Save the doc as a jpeg or giff or whatever and post it up.

[joecar]

Will this help: showthread.php?t=3064 (http://forum.efilive.com/showthread.php?t=3064)

If you don't want to go to a hosting site, replace steps 6-10 with the following:

in your reply, press Go Adavanced, then Manage Attachements,
then Browse, Upload, and Close the Manage Attachments window;

then continue with step 11.

[VetPet]

Here goes nothing.

959

960

961

[TAQuickness]

Couple of things come to mind. If you are not commanding an EQ of 1.0 (AFR of 14.63), the PCM cannot enable long term fuel trimming.

But, before you change your fuel table, try setting B4206 to enabled.

Good job with the screen shots. Pictures are worth 1k words.

[VetPet]

Let me try that again.

962

963

964

[VetPet]

Couple of things come to mind. If you are not commanding an EQ of 1.0 (AFR of 14.63), the PCM cannot enable long term fuel trimming.

But, before you change your fuel table, try setting B4206 to enabled.

Good job with the screen shots. Pictures are worth 1k words.

Thanks bud. I tried to do it again because I thought they didn't come out clearly but then I found out you can enlarge the screen shot. Appreciate the help. Would seem that there's a step missing out of the autove tuning tutorial at this point that needs to be added. Just surprised no one else has run into this problem.

Thanks to JoeCar and Doc as well.

:cheers:

[TAQuickness]

Thanks bud. I tried to do it again because I thought they didn't come out clearly but then I found out you can enlarge the screen shot. Appreciate the help. Would seem that there's a step missing out of the autove tuning tutorial at this point that needs to be added. Just surprised no one else has run into this problem.

Thanks to JoeCar and Doc as well.

:cheers:


I'm not sure I follow you.

[VetPet]

When you've completed getting your BEN's around 1 and then transfer the calibrations from your AutoVE tune to your original tune (B0101),the other change you're told to make is to disable your MAF. There is no mention that you may have to change your open loop fueling table (B3605). As you can see from my screen shot, that table is still the original table in my original tune, not the one you're asked to set up in AutoVE tuning. If your commanded AFR needs to be 14.63 in order for closed loop operation to work properly then you need to modify the Commanded Fuel When in Open Loop AFR's in your original B3605 table or copy the B3605 autove table over to your original tune. Or, enable {B4206} use 02 with open loop commanded fuel table as you mentioned. Hope I've explained myself clearly.

Thanks, :cheers:

[TAQuickness]

When you've completed getting your BEN's around 1 and then transfer the calibrations from your AutoVE tune to your original tune (B0101),the other change you're told to make is to disable your MAF. There is no mention that you may have to change your open loop fueling table (B3605). As you can see from my screen shot, that table is still the original table in my original tune, not the one you're asked to set up in AutoVE tuning. If your commanded AFR needs to be 14.63 in order for closed loop operation to work properly then you need to modify the Commanded Fuel When in Open Loop AFR's in your original B3605 table or copy the B3605 autove table over to your original tune. Or, enable {B4206} use 02 with open loop commanded fuel table as you mentioned. Hope I've explained myself clearly.

Thanks, :cheers:

That's what I needed. Good catch btw. I'll update the tutorial in the near future.

[VetPet]

No problem bro. With all the help you guys give out to a newbie like me it's the least I can do. I'll be making the change to my open loop fueling table tonight to see if that does the trick and will let you know.

:cheers:

[VetPet]

Okay, what gives? I've changed the AFR values in B3605 to match those used in the AutoVE tutorial so that I am getting commanded AFR as 14.63:1 and have also changed B4602 'Use 02 with open loop commanded AFR table' to 'Enabled' and still can't get any LTFT readings. I know that LTFT is enabled and that I'm in closed loop because I used the fuelsystem check pid GM.FuelSys as suggested by Blacky to see what status the fuel system was in. This is really making my head hurt :bash: . Someone please throw me a life line before I drown. The funny thing is that as soon as load my original tune back in I can log LTFT's again. Crickey! :Eyecrazy:

[joecar]

What differences (CAL - ALT) does the Tune Tool show between your current tune (CAL) and your stock tune (ALT)...?

[Blacky]

Are the short term fuel trims working?

Check your short term fuel trim values: Fuel->O2->Paramaeters:

{B4101} Closed Loop Idle Vehicle Speed 6.437378 KMH
{B4102} Closed Loop Idle Vehicle Speed Hysteresis 1.609344 KMH
{B4103} Closed Loop Idle Throttle Position 5.000000 %
{B4104} Closed Loop Idle Throttle Position Hysteresis 0.390625 %
{B4108} STFT Idle Enable Enable
{B4115} STFT Maximum Correction 1.200195
{B4116} STFT Minimum Correction 0.799805
{B4117} STFT Multiplier 1.000000
{B4118} STFT Adjustment at Idle 0.004883
{B4119} STFT Adjustment at Non-Idle 0.007813
Also make sure table {B4106} is not zeroed out, otherwise no LTFTs will get updated.

What I would do is copy ALL values from all tables and parameters in the "TRIM" and the "O2" sections, from the tune that does work with LTFT into your new tune.

Regards
Paul

[VetPet]

What differences (CAL - ALT) does the Tune Tool show between your current tune (CAL) and your stock tune (ALT)...?

It showed about a 2.5% difference between the two.

:cheers:

[VetPet]

Are the short term fuel trims working?
{B4101} Closed Loop Idle Vehicle Speed 6.437378 KMH
My B4101 table value for this is 24.643xxxKMH. The rest of the values match what you show.

Also make sure table {B4106} is not zeroed out, otherwise no LTFTs will get updated.
Here's my B4106 table.
966

What I would do is copy ALL values from all tables and parameters in the "TRIM" and the "O2" sections, from the tune that does work with LTFT into your new tune.
OK, I will do that although the tables and parameters are identical between my tune that works and my modified original tune.

Thanks mate. :cheers:

[TAQuickness]

Vet - Starting on Page 14 of the AutoVE tutorial, are you sure you followed all the steps?

I went to update the tutorial per you comments, but found updating the Open Loop Fueling Table shouldn't be necessary unless your stock OLFT is not = 1.0 or 14.63 AFR.

In this last section, the tutorial has you open your original tune (one of the three copies you made in the begining), disable the MAF, then transfer the modified VE tables.

I'm very curious why this didn't work for you.

If you don't mind, would you send me your final AutoVE tune, plus the original and back up tune created during the AutoVE process? TAQuickness at houston dot rr dot com.

[joecar]

It showed about a 2.5% difference between the two.

:cheers:Which tables/parameters show up as being different...?

[VetPet]

TA, Have sent you an e mail.

Thanks

:cheers:

[VetPet]

Still can't get the LTFT's in closed loop speed density mode. I've taken my original tune that will give me LTFT's when hooked to the scan tool and done the following as per page 14 of the autove tutorial.

1. Copied new VE table from autove tuning into my original tune.
2. Disabled MAF function and MAF MIL codes.
3. Copied High Octane table into Low octane table.
4. Saved tune as closed loop, speed density.

I then checked all of the following tables to make sure that they were as they should be.

1. B3605 - Commanded fuel when in open loop (per original tune)
2. B3313 - DFCO Temp Enable (per original tune)
3. B3618 - PE modifier based on rpm (per original tune)
4. B3801 - Long Term Fuel Trim Correction (Enabled)
5. B0701 - Catalytic conerter protection enbale (Enabled)
6. C6002 - Engine DTC MIL Enablers - P0101, P0102, P0103 set to No MIL
7. C2901 - MAF High Frequency Fail 1 - Set to 1Hz
8. C2903 - MAF High Frequency Fail Limit - Set to 1
9. B4108 - STFT Idle enable - Enabled

I then loaded the tune into my PCM, started the car, waited for the coolant temperature to warm up to 60c and then started monitoring the LTFT's. The readings from the data tab showed a value of zero for both banks. I've verified that the system was in closed loop using the fuelsys. pid and that LTFT learning was enabled. I am at my wits end here and have absolutely no further idea what to do.

:help2: :beer:

[TAQuickness]

are the STFT's moving?

I got your email - just been very busy lately. I take a second look tonight.

[VetPet]

Haven't been monitoring the STFT's. Will have a look tonight when I get home.

Thanks

[SSpdDmon]

Yeah, you should be watching the STFTs. If the tune is dialed in, LTFT's would be zero.

[dc_justin]

Yeah, you should be watching the STFTs. If the tune is dialed in, LTFT's would be zero.

Yep.

Although, I would be absolutely amazed if he had 0.0 LTFTs across the board... Perfect fueling seems impossible, especially with the bank to bank variances that naturally occur...

[VetPet]

I would be absolutely amazed if my trims are perfectly zero across the board as well. I didn't get a chance to monitor the STFT's tonight like I wanted to. I will say one thing, my monitored AFR is tracking extremely close to my commanded AFR. This would tend to make me think that I"ve got my LTFT's in line at least. I'm thinking I should load my original tune prior to recalibrating my VE table via autove tune and put it into closed loop speed density and monitor the LTFT's. The VE table should be out by enough that I should get some LTFT readings. Thanks for your input and support guys.

:cheers:

[Bruce Melton]

Maybe in Scan mode check "n" instead of "x" to confirm you are getting hits?

[VetPet]

Tried to scan STFT's & LTFT's tonight. Not getting any information on either. Checked my LTFT Maps and was getting no hits or data. I have LTFT & STFT enabled, MAF disabled. This is really getting on my nerves and I'm a very patient guy. This is really ridiculous. I don't know what else to do. If anyone has a suggestion I'd be more than glad to hear it.

Thanks:bash:

[joecar]

Possible strategy:

0. copy your original factory tune to file TEST.TUN (and lets call your current tune NEW.TUN);

1. cal-only flash TEST.TUN into PCM, and see if LTFT/STFT now work;

2. if that failed, then full flash TEST.TUN into PCM, and see if LTFT/STFT now work;

3. if that failed, then need to diagnose O2 sensors and related circuits/sensors (e.g. ECT sensor);

4. otherwise LTFT/STFT are now working, copy a few tables from NEW.TUN into TEST.TUN and cal-only flash into PCM;

5. if LTFT/STFT is still working, goto step 4.

[VetPet]

The mystery has been solved and I feel like a total idiot. All this time I had been expecting to see LTFT values when the car was idling when in fact, you won't see any until your speed surpasses the value set in B4101, closed loop vehicle idle speed. My value was around 24km so I wouldn't get any LTFT learning to start until I went at least that speed and faster. I hadn't paid any attention to this parameter, only the STFT to see if was enabled. Changed the value to 1kmph so I could initiate LTFT sooner and went out to log some data and of course, there were my LTFT's. My sincerest thanks to everyone who responded with help. Only had time for a short drive but my LTFT's are in the negative range. I'll have to do some long term driving to get more accurate numbers but at least it's working.

:cheers: :D

[Bruce Melton]

Well Hmmm- I always get LTFT readings at any rpm and standing still, as in 0 speed?

[VetPet]

I'm going to set my B4101 table to 0kph and see if I get readings at idle. All I know is that's the only change I made and I started seeing LTFT's again. Before I did this I also wasn't getting any STFT readings either. What's your B4101 parameter set to?

:cheers:

[Bruce Melton]

I'm going to set my B4101 table to 0kph and see if I get readings at idle. All I know is that's the only change I made and I started seeing LTFT's again. Before I did this I also wasn't getting any STFT readings either. What's your B4101 parameter set to?

:cheers:

992

[VetPet]

Your B4101 table has the same value in it that mine had before I changed it. I'm going to try to set it back to where it was and see what happens tonight.

:cheers:

[Bruce Melton]

It may take some engine temp before it starts logging. Also make sure you are recording not monitoring.

[VetPet]

I didn't realize that you had to be recording the data, not monitoring it in order to your LTFT's. All my other PIDs show data when I'm monitoring only.

:beer:

[TAQuickness]

if you're looking at the data tab while monitoring, you should see the pid's updating. dash and map pages don't updated while monitoring.

[VetPet]

Here's an interesting dilemma. I finally got the LTFT's to work but only when I log certain pids. If I use the autove pids and then add the LTFT pids I get no data. I tried again last night to log my LTFT's using the autove pids with LTFT pids added. I could not get any data even though I was getting cell counts. I'd like to attach my log files for someone to look at but my pop up blocker won't let me. I'll try to post from my desktop when I get a chance. I was having some problems with my flashscan unit when I tried to upload my tune several time. I would get a message that said the flashscan unit could not be found and that I should try checking my connections and reattaching them. Is it possible that my flashscan unit is not working properly and that's what's causing my problems?

Thanks :cheers:

[TAQuickness]

Where are you trying to view data from (i.e. data tab, map, chart)? If you're viewing a MAP, are you sure the hide cells is not active?

[VetPet]

I'm looking at the Data tab when I'm viewing the information during monitoring. Once I start recording data I'm able to see the cell counts and the values in my LTFT MAPS. If I can see the LTFT data when I'm using the pids in one set of pids I should be able to see them when I've inlcuded them in a different set of pids. Shouldn't I?

:beer:

[TAQuickness]

check you mail.