backround tcc tables

[poulina]

Submitting a new thread to try to diagnose an intermittent TCC enable command. I have all the available channels related to torque converter control displaying in my scanner channel list.

My ecm will not apply the tcc even though I will be driving well within its enabled parameters (speed, tps, etc)

This is an intermittent issue, meaning different drive cycles it will apply the converter like its supposed to, and other times it wont. I can always apply it manually via the special functions in the scanner. Usually after I write a new file it will be happy and apply, but after a dozen or so drive cycles it "learns" to not apply. Ive changed most every table in the torque converter tab within the Transmission side of the editor, to no avail.

I am somewhat convinced there is something going on in the background that the ecm is learning to not apply the tcc, if anybody has heard of anything like this and would care to share that would be nice.

This is a turbo 5.3/6l90e application, it makes power pretty low in the powerband. Might something in the virtual torque tables affect how the trans applies the tcc?

wont lockup.hpl

I manually applied the converter in the log posted above

[TransGo Robert]

Submitting a new thread to try to diagnose an intermittent TCC enable command. I have all the available channels related to torque converter control displaying in my scanner channel list.

My ecm will not apply the tcc even though I will be driving well within its enabled parameters (speed, tps, etc)

This is an intermittent issue, meaning different drive cycles it will apply the converter like its supposed to, and other times it wont. I can always apply it manually via the special functions in the scanner. Usually after I write a new file it will be happy and apply, but after a dozen or so drive cycles it "learns" to not apply. Ive changed most every table in the torque converter tab within the Transmission side of the editor, to no avail.

I am somewhat convinced there is something going on in the background that the ecm is learning to not apply the tcc, if anybody has heard of anything like this and would care to share that would be nice.

This is a turbo 5.3/6l90e application, it makes power pretty low in the powerband. Might something in the virtual torque tables affect how the trans applies the tcc?

wont lockup.hpl

I manually applied the converter in the log posted above

I am in my phone right now so I can't look at the log. But one thing that would really help would be for you to post a log of when it command lock up as it should and then one when it does not. 99% on GM stock applications (yours might not be stock so there could be other causes) when it does not command lock-up it is because either it detected misfires, a lean condition, or the coolant or transmission temperature sensor reads too low.

I'll look at you log tomorrow, but if you have one of each it would make it a breeze to see which input to the computer is causing the issue.

[hjtrbo]

Need that stock tune mate

[hjtrbo]

I second Robs comments. For example in my calibration fluid temp 20degC or below will keep me out of lock up. I'm not sure what yours is set to, I'd have to have a dig to find out.

Some checks for you to try... Anything that doesn't work you can switch back.

Make sure these drop downs are stock:

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Match up your trans vss revs to your engine vss revs:

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Take back to stock:

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[TransGo Robert]

Submitting a new thread to try to diagnose an intermittent TCC enable command. I have all the available channels related to torque converter control displaying in my scanner channel list.

My ecm will not apply the tcc even though I will be driving well within its enabled parameters (speed, tps, etc)

This is an intermittent issue, meaning different drive cycles it will apply the converter like its supposed to, and other times it wont. I can always apply it manually via the special functions in the scanner. Usually after I write a new file it will be happy and apply, but after a dozen or so drive cycles it "learns" to not apply. Ive changed most every table in the torque converter tab within the Transmission side of the editor, to no avail.

I am somewhat convinced there is something going on in the background that the ecm is learning to not apply the tcc, if anybody has heard of anything like this and would care to share that would be nice.

This is a turbo 5.3/6l90e application, it makes power pretty low in the powerband. Might something in the virtual torque tables affect how the trans applies the tcc?

wont lockup.hpl

I manually applied the converter in the log posted above

I just looked at it, the transmission temperature was pretty low in that recording, but probably not low enough to prevent lock-up. But definitely be sure to have it get to operating temperature next time you take a log. The coolant was also not up to operating temperature yet, so that needs to be met first before we can figure out anything. You need to also include the long term fuel trims, short terms only are not going to cut it. Lastly, if this is a stock 6.0L engine your MAF is reporting twice as much as it should, that's a major issue, the load can't be calculated correctly and that directly affect the lock-up command.

[poulina]

thanks for the replies ill share my stock file later today. this is a turbo 5.3/6l90e in a obs chevy truck, so I have some stuff changed/turned off to make it happy (like LTFT).

could my vve table be so off that it isnt agreeing with other tables and not allowing lockup? so strange and frustrating there is background stuff like this.

[TransGo Robert]

thanks for the replies ill share my stock file later today. this is a turbo 5.3/6l90e in a obs chevy truck, so I have some stuff changed/turned off to make it happy (like LTFT).

could my vve table be so off that it isnt agreeing with other tables and not allowing lockup? so strange and frustrating there is background stuff like this.

That's above my pay grade, I deal mostly with stock stuff normally. But on a stock applications, when the long term fuel trims go too far away from zero (usually plus or minus 10 or so) it stops commanding lock-up to protect the engine.

[04silverado6.0]

You showing any misfires?

[hjtrbo]

Make those checks / changes I said. If you don't I won't comment any more if that's what you prefer.

[hjtrbo]

For reference, these are headline conditions that keep it unlocked. There are more that will transition the state machine into unlock if locked. The below represents a snippet of weeks of work and serious head scratching inside my os / cal, what that really means is don't ask me to bury into your specific os / cal.

void TCC_Mode_Transitions_OFF(void)

{
  _FullReleaseState = false;
  if (((!_b_LockEnbl) || (!_b_Active)) || (_b_UseMinThrot)) {
    Off_Transitions_MinThrot();
  }
  if ((_b_LockEnbl == false) || (_b_Active == false)) {
    Off_Transitions_DG_MinThrot();
    Off_Transitions_AltitudeApplyDly();
    Off_Transitions_MinThrotReApplyDly();
    Off_Transitions_ReleaseOffNegDltaThrot();
    __Off_Transitions_TransTempHighOff();
    Off_Transitions_EngCoolTempLow();
    Off_Transitions_ShiftCommanded();
    Off_Transitions_DG_Upshift();
    Off_Transitions_LowSlip();
    RampOff_Transitions_PosDltaThrot();
    Off_Transitions_AmbientAirPresLow();
    Off_Transitions_ShiftStabilization();
    Off_Transitions_Range();
  }
  Off_Transitions_TransTempLow();
  Off_Transitions_BrakeOn();
  Off_Transitions_ImmedOffDsrd();
  Off_Transitions_CntrldOffReApplyDly();
  Off_Transitions_ForceOffDiag();
  Off_Transitions_MisfireTest();
  __Trnstns_CntrldOffSlew__();
  Off_Transitions_PCA_PresHigh();
  SetBitIf_TCCFullReleaseState(&_Off_Transitions_MaintainOffMode_,0x19);
  Off_Transitions_MaintainOffMode();
  SetBitIf_DesiredState_CONTROLLED_ON(&_EnblOnTrnstns_CntrldOnDsrdEnblOn_,0);
  EnblOnTrnstns_ForceAppDiag();
  EnblOnTrnstns_CntrldOnSlewEnblOn();
  OnTrnstns_ImmedOnDsrd();
  OnTrnstns_HiSpdReq();
  LockOnTrnstns_ManualSlewLockOn();
  _VCC_SlipReleaseCnt();
  _t_MinThrotBusyCnt = 0;
  Off_Transitions_TCS_Request();
  return;

[poulina]

Well I’ll be a darn fool my ecm and tcm vss values were not the same….the tcm had the correct value but the ecm didn’t. I sure hope that was the problem I’ll report back. Thank you for the replies

[poulina]

Curious how it could have locked up at all? If the tcm and ecm had completely different values.

[poulina]

I did show a few misfires but nothing extraordinary, I went down that rabbit hole and didn’t find much. I have heard of excess misfires not allowing lockup tho. Thanks for the suggestion

[TransGo Robert]

Well I’ll be a darn fool my ecm and tcm vss values were not the same….the tcm had the correct value but the ecm didn’t. I sure hope that was the problem I’ll report back. Thank you for the replies

Glad you found something, that must be it. Strange that it would work for a bit and then stop commanding it tough.

[poulina]

Thanks for this

[hjtrbo]

Match up your trans vss revs to your engine vss revs

It worked?

[poulina]

It worked?

Went on a drive this morning to see if it would lockup and it did not, setting the ecm vss to the correct value didn’t make any changes to my knowledge. Peculiarly, I shut the truck off to get my coffee, went back to driving and it locks up as it should. Which leads me to think it may be a temperature value that the tcm doesn’t like.

Usually it doesn’t like to lockup first thing in the morning (fluids @ ambient temperature) and when it’s warm it’ll lockup as it should, now this isn’t always the case, but since I have been acutely aware of this issue it’s what I am observing.

I have now set the “limit torque management” enable temperature to -40. Hopefully that will make a difference. Thank you hjtrbo for the help. Will report back.

[hjtrbo]

ok. We're left with temperature, misfires and your shift pattern selection.

• For the misfire stuff, are you stock cam?
  
  • If not, is it aggressive?
  • If stock, we need you to get the misfire counts to get to 0 so we can rule that out.

• For the temperature related aspect, can you blank off airflow to the cooler and log? No need to be silly, if it's not locking up at 53degC it ain't locking.

• Really need to confirm the pattern selection is stock.

[poulina]

srry took me so long to post files;iron5.3 trans tooned 800 idle modd airflow min modified pe maf2 ve1.hptgmcoriginal.hpt

note: MUCH has changed from the stock file to the one I have currently in the truck, so if I have something completely wack or out of place please confront me about it lol

The misfire log touch 10-20 during a drive cycle. I have tried looking for a correlation between misfires and the TCC lockup command, but didnt notice any relationship? I only logged total misfires should I do another test logging every cylinder?

I have a turbo cam in it, under 230 duration, 117 LSA and .625" lift, nothing crazy.

I have noticed a relationship between me trying to dial in my idle airflow in the "min airflow tab" and TCC lockup? Ill make a change to table [ECM] 12087 and everything will be happy, but after a half dozen to a dozen drive cycles itll "learn" not to lockup.

The trans will increase to operating temperature (53C) and the TCC command issue will continue (.wont lockup even at temp). Not sure I understand the test you are suggesting/

Thank you

[hjtrbo]

Don't worry about my temp test. You're getting temp.
There is a min throttle condition they'll keep you out of lock up. You might be onto something there. But I would say that if the min airflow is such a high value it keeps you out of lock up then that needs to be researched as to why you're having to do that.
I'm away for a few days so can't look at your files.
I'll have to let you decide if the mis fires are cam related or if there's a genuine issue there. It's not normal to see those numbers you're getting. There are misfire test tables you can tweak if cam related.