TCC Questions
Thread Starter
On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
TCC Questions Hey guys, so I just started logging my TCC lockup and I noticed something odd (to me anyways), my TCC is just about always locked after 8 MPH, even on relatively hard pulls (65% throttle and 4,500 RPM). Is this normal? Would there be any advantage to changing it or should I just leave it be? I attached my latest log file if anyone wants to have a look
Thread Starter
On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
Yeah, I figured it wasn't right but its been hard to find good info on how to tune the converter lockup, thanks for confirming. Here's a copy of the tune(the converter lockup section and shift points (besides WOT) are all factory as far as I know, I can't imagine this vehicle was tuned before I got it)
I'm far from a professional, but taking a glance, the TCC tables all look "normal".
Minimum TCC lockup is commanded at 29 mph in 3rd gear
I'd probably try manually controlling/commanding TCC Lockup with the VCM Controls feature, while logging.
That should help determine whether it's a mechanical or electrical issue.
I'd add some more transmission related channels as well.
Input/Output shaft RPM, TCC Slip %, Current Gear, etc...
If the converter was truly LOCKED at 8mph, the van would have very poor acceleration from most any RPM
Minimum TCC lockup is commanded at 29 mph in 3rd gear
I'd probably try manually controlling/commanding TCC Lockup with the VCM Controls feature, while logging.
That should help determine whether it's a mechanical or electrical issue.
I'd add some more transmission related channels as well.
Input/Output shaft RPM, TCC Slip %, Current Gear, etc...
If the converter was truly LOCKED at 8mph, the van would have very poor acceleration from most any RPM
Thread Starter
On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
So to add to the mystery, I commanded the lockup clutch off, and it stayed off! the vehicle drove totally different, so I think I can say its something to do with my tune 
Now I get to search through that and find the culprit, do you have any guesses on where to start? I wouldnt say the acceleration is TERRIBLE, but it's not exactly what I was expecting from the LQ4 I dropped in there
Now I get to search through that and find the culprit, do you have any guesses on where to start? I wouldnt say the acceleration is TERRIBLE, but it's not exactly what I was expecting from the LQ4 I dropped in there You don't say what ECM/PCM/TCM if any, or trans you are using. Assume you are using some sort of 4 speed trans....with lock up...
Here is a great tutorial. Scroll down to the torque converter section.....
https://ls1tech.com/forums/automatic...tm-w-pics.html
T,
Here is a great tutorial. Scroll down to the torque converter section.....
https://ls1tech.com/forums/automatic...tm-w-pics.html
T,
Thread Starter
On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
Hey Tom, thanks for the link, I already came across that in my searches and it has some great info, just not exactly what I'm looking for. They cover the pressure and pwm part of it, but not when to apply/release (unless I just missed that part...). I'm using a 4l60e trans, as for ecm, I'm not sure, it's whatever came stock in a 2004 express, I can check next time I have my laptop in the van
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Hey Tom, thanks for the link, I already came across that in my searches and it has some great info, just not exactly what I'm looking for. They cover the pressure and pwm part of it, but not when to apply/release (unless I just missed that part...). I'm using a 4l60e trans, as for ecm, I'm not sure, it's whatever came stock in a 2004 express, I can check next time I have my laptop in the van
T,
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On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
And that's what I get for just skimming through, it was right there staring me in the face. Thanks for all of the help, I cant wait to go try some of this out and hopefully get this figured out