E38 SD TCS Patch Issues

[swingtan]

Hi Guys,

I've been playing with SD on the E38 and come across an interesting problem. I'm testing on a manual car and applied both TCS patches and performed a full re-flash. Now when performing acceleration tests and changing from first to second, I get a huge stutter just as I get back on the power after the gear change.

The first time it happened, Jezza an I thought it may have been fuel surge as the tank was low and I'd just performed a left turn. But it happens nearly every time I do a gear change after letting it rev out a bit. Quick changes at lower RPM's don't see the stutter, only when there's a good chance of traction loss on a gear change.

Before anyone asks, yes the TCS was switched off using the console switch, so it should not be active. Turing the switch off when running without the patches ( and with the MAF enabled ) results in good powerful shifts with no torque reduction.

To test out my theory that the patches may not be working correctly, I disabled all TCS settings in the tune and set the TCS enable RPM to 8000. I then went out again to see what the difference was. This time, not stutter. I've attached some log segments to show what is happening.

log_TCS.efi shows the stutter on gear change, in it you can see...

• The throttle opening rate slow down. ( remember this is an ETC vehicle ).
• A sharp drop in spark advance.
• fuel mixture leaning right out. Though I'm guessing that this was more due to the rapid throttle opening.

the only TCS settings enabled in the tune for this were TCS reduction by spark and TCS reduction by throttle. TCS reduction by fuel was disabled. Again, remember that traction Control was turned of by the switch for this run.

log_no-TCS.efi shows no stutter at all

Any idea's on this one? I must admit I almost needed a change of pants after the first time it happened.

Simon.

[GMPX]

Grab the latest .cal files from here -
http://forum.efilive.com/showthread.php?t=5540

Look for B0530 - B0532.
Not sure what vehicle you have there though?

Cheers,
Ross

[swingtan]

Hi,

I just updated the cals and checked those settings. All are set to no. However B0527 and B0529 are set to yes. The thing is, this only started after trying SD tuning and applying the 2 patches, B9901 and B9902. If I get a chance I'll try removing them and re-enabling TCS to see if it still occurs.

The vehicle is an L76 ( 2006 VZ ). Thanks for the tip on the cals though, seems to be a bit more in there to play with.

Simon.

[The Alchemist]

JUST TUNING A ve HOLDEN AND i HAVE THE SAME PROBLEM ALTHOUGH it doesn't seem to be related to a Mafless patch. Over 3000rpm I can nail it and no stutter but under say 2000 rpm its really bad and you can't even get 50% throttle. Its not torq control as I lifted the limits very high to over 1000nm....This has a 224 cam in it though which changes things a wee bit
Disabled b0530,31,32 and it still does it. Will reflash with each one turned off to see what one of the TCS is doing this..... update this afternoon......Its does it regardless of the ECS switch being on or off too , Axle protection, wheel hop and clunk reduction.....

Hey GMPX > do these different TCS "types" also have modifier tables associated with them linked to say delivered torq vs TPS or something similar that you are still "extracting" out of the GM code? Also in B5123 the explanation refers to "desired coast down rpm" which suggests there is a table for desired coast down RPM available....are these things sort of in the pipeline so to speak.....?

[The Alchemist]

TRYING TO ATTACH A Jpg file with a log....
right that worked.....
Turned off all TCS from b0515 to b0532 and enabled the MAF back on line and it still won't allow even 30% throttle under 2500rpm without spark retard, it even does it at a constant speed at 1800rpm, as per the log, causing a light miss at cruise.


Any ideas people.

Mike

[Black02SS]

Hi,

I just updated the cals and checked those settings. All are set to no. However B0527 and B0529 are set to yes. The thing is, this only started after trying SD tuning and applying the 2 patches, B9901 and B9902. If I get a chance I'll try removing them and re-enabling TCS to see if it still occurs.

The vehicle is an L76 ( 2006 VZ ). Thanks for the tip on the cals though, seems to be a bit more in there to play with.

Simon.

I have the same problem here on my 07 Vette. I thought it was because the weather got crappy and I wasn't able to finish the tune. Hmm..

[The Alchemist]

Hi people I just reflashed with my last changes which was to raise the TCS on limit to 8000rpm, everything else is "off" and its as bad as ever !!!!!!!!! Can't nail it at all, you can only very gradually bring in the throttle until 2500rpm then nail it. It also seems directly proportional to rate of change of the TPS, the quicker you nail it the more aggressive the spark cut
Mike

[The Alchemist]

http://forums.corvetteforum.com/show...1361913&page=4

look what I found on a US forum site.........
Brake torq limit vs vacuum vs TPS....
perhaps this is the "missing" table.......

[dynarex]

ran several tunes and all is well-but i noticed that the tables b8034,b7902,3,4 all are out of range
so i tried to adjust and they wont go over the max limit-so i said forget it and loaded the tune-well the truck died
i limped it home and read the codes -then checked the history and the tables that i tried to adjust said i changed the values from numbers way above the efi limits even though i didnt change them
this is on a 2008 sierra 1500 l98 auto with the e38ecm
sorry for being unclear -will fix my sig
_dont touch these tables-there is an error in the way efi reads them!!!_________________

[The Alchemist]

b2522, finally turned off TCS completely. Simply put zeros in it so TCS is still activating but pulling zero timing....dangerous but fun at the same time in a car making 295kw!!! at the wheels.
If the table in my earlier post is "missing" but becomes available then it would be better, safer, to leave TCS enabled but raise the maximum torq limits in the problem area of low revs/high vacuum. The car hauls now and would be dangerous in the wrong hands without TCS. Breaks loose in 3rd when it hits the cam.