TQ lockup questions

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
More driving tonight traction control off = good traction control on = bad any ideas why?

When stabilitrak is enabled, every torque request is inter-mediated by the EBCM (abs module). When you step on the pedal and tell the ECM to "jump", the ECM asks the EBCM, not your right foot, "how high".

I mean think about it. The stability control's #1 job is to keep the truck from oversteering, understeering, losing traction, preventing wheel-spin, and preventing rollover. What does it need to keep the truck off its lid and going in the drivers-intended path? Complete control of the engine's power output. With stabilitrak enabled, everything operates just a little bit more cautiously and conservatively.

ben
 

Evan@InglewoodTrans

yerp
Vendor/Sponsor
Aug 5, 2010
3,118
65
48
40
Western MA
Hey dude, put ToTheMax01 back on, he was much more literate than you are. I read the above post three times over and still couldn't make any sense of it.

Are you afraid that we might meet in person at some point? Thats why you had to go hide behind a fake screen name to take a dig at me??? Better hope that awesome "stage 2" you got under your truck holds together...because George is a much farther drive from you than I am.

My products and my customers' trucks' performance speak for themselves. I dont need a big stupid money pit of a truck to show off and prove my worth as a diesel performance shop. And for what its worth, my truck was running 12's almost 5 years before yours was.

Happy customers with fast trucks is probably the best advertising a shop could possibly have IMO. My truck doesnt run 10's or pull in the 3.0 class but it is unique, its mine, and it has many one-off custom parts that no other Duramax's in the world have.

And if you look around, the some of the best shops/leaders in the duramax/allison performance world have daily drivers that are even more stock than my truck. ;)
first off afraid to meet you no thats not quite it as scary of a guy as you are lol in fact if you like pm me i will give you my number we arent that far away from each other.Second i would hope your truck ran 12's before mine when ive only had the truck since spring and it was bone stock.All the performance trucks you have running around really do speak for themselfs and that innovative foot actuated dimmer has shaved time off many a quarter mile.oh and by the way my stage 2 is just fine :thumb: and dont worry you would be the last guy to touch the truck and like i said im not going to get into a internet sh*t talking war with you just pm me
 

turbojamie

Member
Dec 7, 2009
101
0
16
When stabilitrak is enabled, every torque request is inter-mediated by the EBCM (abs module). When you step on the pedal and tell the ECM to "jump", the ECM asks the EBCM, not your right foot, "how high".

I mean think about it. The stability control's #1 job is to keep the truck from oversteering, understeering, losing traction, preventing wheel-spin, and preventing rollover. What does it need to keep the truck off its lid and going in the drivers-intended path? Complete control of the engine's power output. With stabilitrak enabled, everything operates just a little bit more cautiously and conservatively.

ben



I agree with you 100% but I was under the impression if it wasn't flashing the traction control light that it wasn't sensing it. Which I now beleive I am wrong on and it doesn't necessarily trip the traction control light when its sensing whatever it is. I'm only guessing here but maybe I am wrong that your box won't help my situation, I am also guessing there is no way to disable or otherwise work around the traction control besides pulling the fuse for the EBCM? If that were done what else on the truck is lost?

Can the EBCM be disabled with a fuse pull, then turn off the DIC light with efi live?
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
I agree with you 100% but I was under the impression if it wasn't flashing the traction control light that it wasn't sensing it.

nooo...the EBCM is always playing traffic-cop as far as torque signals and power requests go. ;)

The light itself only comes on when there is a significant/major VSES (vehicle stability enhancement system, ie, stabilitrak) event. Many times it will be making minor 'corrections' and be giving the truck small amounts of help to maintain course without flashing the light. If it flashed the light for every time it intervened drivers would find it annoying and complain to the dealer.

Which I now beleive I am wrong on and it doesn't necessarily trip the traction control light when its sensing whatever it is. I'm only guessing here but maybe I am wrong that your box won't help my situation, I am also guessing there is no way to disable or otherwise work around the traction control besides pulling the fuse for the EBCM? If that were done what else on the truck is lost?

Can the EBCM be disabled with a fuse pull, then turn off the DIC light with efi live?

Press and HOLD the traction control button for 6 seconds. THIS IS THE KEY PART that everyone misses because no one bothers to read the owners manual. It would only be intutive that you "press the button once, light comes on, it must be all off!!"...but thats not the case. You press the button once, and it only turns the 'straight line/wheel-spin' traction control off. Stability/yaw control is still on.

When you press the button and hold it until it says stabilitrak OFF, then you are complete free. Obviously you still have ABS functional though.

Either that or pull the ABS/VSES fuse. But if you pull that you will not have any ABS, and you will NOT have any rear brake proportioning. Remember, there is no proportioning valve on these trucks. ;) Front/rear brake bias is completely dynamic and done wholly by the EBCM. If you stop on the brakes with the EBCM disabled, the rears will lockup so fast before the front brakes even begin to start doing anything.

Ben
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
Also, with the ABS fuse pulled, you've got nothing to give the TCM an unlock-request.

So if you are driving along on the highway, ABS disabled, converter locked up, and you slam on the brakes and lock them up, the TCM never gets told "hey, the wheels are locking up, you better release the TC" and the engine will stall because its just like if you locked up the brakes on a manual trans car without pressing the clutch in.
 

turbojamie

Member
Dec 7, 2009
101
0
16
Also, with the ABS fuse pulled, you've got nothing to give the TCM an unlock-request.

So if you are driving along on the highway, ABS disabled, converter locked up, and you slam on the brakes and lock them up, the TCM never gets told "hey, the wheels are locking up, you better release the TC" and the engine will stall because its just like if you locked up the brakes on a manual trans car without pressing the clutch in.

^^^ That just plain sucks no real work around at all.



Damn sounds like there is physically no way around this stupid traction control except with holding down the button until you get the whole shootin match disabled. I guess then I should be re setting taps and do all my driving with the whole system shut down.

I was hoping that it could just be turned off however I guess GM figured we would try to get around it sucks!

Can the trucks be flashed with 08 ECBM software to get rid of it? My dads 08has none of this crap! Or can modules be bought and swapped etc to make this Traction control go away ?
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,755
5,930
113
Phoenix Az
^^^ That just plain sucks no real work around at all.



Damn sounds like there is physically no way around this stupid traction control except with holding down the button until you get the whole shootin match disabled. I guess then I should be re setting taps and do all my driving with the whole system shut down.

I was hoping that it could just be turned off however I guess GM figured we would try to get around it sucks!

Can the trucks be flashed with 08 ECBM software to get rid of it? My dads 08has none of this crap! Or can modules be bought and swapped etc to make this Traction control go away ?

that or i know some guyes were tryin to devise a relay deal that was timed for when you start the truck, it clicks a relay on (the relay would take place of your button in a sense) for 6 sec to disable it everytime you get in the truck but you will still get the light and message everytime. I dont think you can just change the BCM without loosing some other creature comforts that are also in the package that traction control is in.
 

scratchrob13

<---30+ psi (both)
Jun 18, 2008
129
0
0
Boston|Suffield,CT|Lincoln,NH
I mean do you go WOT every time you get into the truck? For DD'ing around town it shouldn't be an issue, and if you want to do silly pulls, then push the button.

I know whenever I get in an ESP car, I usually push the button if I am going for a spirited drive, if not I just leave it alone.
 

Redbowties88

Sideways > Straight ;)
Aug 24, 2009
1,943
1
0
609 New Jersey
If you stop on the brakes with the EBCM disabled, the rears will lockup so fast before the front brakes even begin to start doing anything.

Ben


found this out the hard way :( first vehicle ive ever owned to not have its abs disabled for more then a day or 2.


ben if you wanna make up something to help that would be killer ;):angel:
 

GeneralTJI

Turbo Todd
Jun 1, 2010
1,272
0
36
Colorado
I must have some sort of super TCM or something. Mine never shifts funny at WOT unless I change tunes. As far as I know the TCM has separate TAP cells for different throttle positions. It shouldn't change the TAPs for WOT unless you change the WOT fueling.

I was wondering this too... I can see the preset tap values for each gear and they are broke up by 0% TPS, 50% and 100% (i'm using HP Tuners but I'm sure EFI has access to these too)

In theory putting around shouldn't effect WOT TAP values... but I don't know if that really holds true?
 

turbojamie

Member
Dec 7, 2009
101
0
16
I mean do you go WOT every time you get into the truck? For DD'ing around town it shouldn't be an issue, and if you want to do silly pulls, then push the button.

I know whenever I get in an ESP car, I usually push the button if I am going for a spirited drive, if not I just leave it alone.

No not at all but I think its messing with me at part throttle the truck is pretty powerful and does loose traction somewhat easily. I'm not very nice to it. I could also be having some minor fuel issues running a 450 rwhp tune waiting on my lift pump could be delaying some shifting he he .
 
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scratchrob13

<---30+ psi (both)
Jun 18, 2008
129
0
0
Boston|Suffield,CT|Lincoln,NH
No not at all but I think its messing with me at part throttle the truck is pretty powerful and does loose traction somewhat easily. I'm not very nice to it. I could also be having some minor fuel issues running a 450 rwhp tune waiting on my lift pump could be delaying some shifting he he .

I would take EFI and log the rail pressure, to make sure you aren't starving the CP3 a lot... you'll end up doing more damage to that by starving it without the lift pump.

Who's tune is it? And do you know how much fuel/timing is being thrown at it? And what are you waiting for on the lift pump?
 

turbojamie

Member
Dec 7, 2009
101
0
16
I would take EFI and log the rail pressure, to make sure you aren't starving the CP3 a lot... you'll end up doing more damage to that by starving it without the lift pump.

Who's tune is it? And do you know how much fuel/timing is being thrown at it? And what are you waiting for on the lift pump?

Lit pump ordered on its way to me right now! Not waiting at all, logged pressure seems fine but... Im still new at this.
 

turbojamie

Member
Dec 7, 2009
101
0
16
Do you have a log of your rail pressure at WOT handy?

I do however I dunno if Rob wants me sharing that stuff...

Desired is 26,107

Rail pressure is at 23,983 but then goes up to 26,100 so I think that means Im ok thats at 100% throttle at the peak lbs/m on the maf, which is 62 lbs/m

The system peaks at that 62 lb/s m then drops down to around 59 that is probably my boost spike, on the peak rail pressure is below commanded however as soon as airflow drops to 59 my rail pressure and commanded equalize, is that good?

Edit the more I look at it I see frame by frame my desired is about 100 psi higher than the rail pressure so I am guessing that I am at the edge of the fuel system. Gonna back her down to 400 tune for now till AD 165 shows.
 
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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,755
5,930
113
Phoenix Az
I do however I dunno if Rob wants me sharing that stuff...

Desired is 26,107

Rail pressure is at 23,983 but then goes up to 26,100 so I think that means Im ok thats at 100% throttle at the peak lbs/m on the maf, which is 62 lbs/m

The system peaks at that 62 lb/s m then drops down to around 59 that is probably my boost spike, on the peak rail pressure is below commanded however as soon as airflow drops to 59 my rail pressure and commanded equalize, is that good?

Edit the more I look at it I see frame by frame my desired is about 100 psi higher than the rail pressure so I am guessing that I am at the edge of the fuel system. Gonna back her down to 400 tune for now till AD 165 shows.

You will never hold exaclty the desired level for rail pressure. if at WOT your desired is at 26k and your actual is 100 less and holding all the way through the RPM in 4th and 5th gear your doin damn good and should have nothing to worry about. A lift pump is a really good idea though should your go higher in tuning and jsut for longevity of the pump at those high levels. Your CP3 sounds like its in great shape :D
 

turbojamie

Member
Dec 7, 2009
101
0
16
You will never hold exaclty the desired level for rail pressure. if at WOT your desired is at 26k and your actual is 100 less and holding all the way through the RPM in 4th and 5th gear your doin damn good and should have nothing to worry about. A lift pump is a really good idea though should your go higher in tuning and jsut for longevity of the pump at those high levels. Your CP3 sounds like its in great shape :D

Sweet I thought maybe the rail pressure should exceed commanded to be on the safe side. No dropping at all, I just thought it should exceed it for safety buffer zone.