TCC Lock Up 6L80E

[TYRFRYR]

Just curious if anyone could shed some light on why the TCM wont command lockup while @ 60mph in cruise control?

TPS = 29-30%
MPH = 60

[LSX378]

Just curious if anyone could shed some light on why the TCM wont command lockup while @ 60mph in cruise control?

TPS = 29-30%
MPH = 60

Took a peep at your log.

What are you logging that indicates that it is not "locking"?

In the A6, you need to log slip & or PWM duty cycle. These dont appear to be in the log, and commanded gear is missing as well.

but...just had a quick look....

[TYRFRYR]

I can tell it's not locking based on engine rpm. In 6th gear, 60mph is 2000 rpm unlocked and 1500-1600 locked.

[midevil1]

From looking at what your tranny tune has at Normal mode. It can't be unlocking. Maybe you are feeling the 5th gear drop. 60 mph is about right for a stock setup. Unless, you turn up the pressure (not recommended) in the 6th gear shift. They feel virtually the same.

[TYRFRYR]

Thanks, but it is the converter. If I force it to lock, it locks and the RPM drops to 1500. When I undo the force, it unlocks and the RPM jumps up to 2000.

[8850]

With all the changes you've made to the tranny tune something might be skewing your converter locking commands. I would put the stock tranny tuning back in and work from there.

[midevil1]

Well, GM never meant it to operate this way. I would start over.

[pmj341]

explain start over??

[midevil1]

explain start over??

His tune.....start back from stock.

[Nick 2K2 SS]

Thanks, but it is the converter. If I force it to lock, it locks and the RPM drops to 1500. When I undo the force, it unlocks and the RPM jumps up to 2000.

Have you tried forcing it into 5th with a locked converter to see what that RPM is? Maybe 5th with a locked TCC is the same as 6th with an unlocked? Just a thought?
I've been adjusting the TCC on my GXP the last few nights and studying the shift tables you really need to study both the shift speed tables (MPH when the shift occurs) and the TCC apply/release tables at the same time.
I noticed in my car that 3rd gear was set to lock at 35mph and then unlock at 34mph for the same TPS%. I lowered my 3rd gear release to 30mph so it wouldn't be teater tottering between locked and unlocked. I think my 4th gear lock/release at lower TPS settings was the same way so I lowered the release a few mph in 4th as well. But with all of the TCC settings you want to make sure that you don't set one to release at a lower MPH than a down shift or else it will never release in that gear once it is locked. It will just down shift on you. I hope some of this helps you.

[xstang]

Not sure if this helps, but If I keep TM enabled (three main switches), the converter won't lock. Soon as I disable those three switches, it locks/unlocks as commanded.... I have a 2008 C6...