how is TCCDC% determined
My truck had been shifting fine, then I installed 4.56 gears last week. It seemed to be locking up real hard, then had almost a chatter to it when it was locked up. Well yesterday it seems to have stopped locking up all together. I logged a run (I can post it if it will help), and it shows that it is locking up, but it does not feel like it, and the RPM's are not dropping when it is showing locked. I assumed it was calculated by the input and output shaft.
I just decided to post a quick log. Here are a couple part throttle runs through the gears. I just paused it as soon as it showed to be locked up. Thanks
I see in the log it is not locking... I can't see the reason.
Joe, thanks. I guess I was reading it wrong. It showed 99.2%, and said locked so I assumed it was locked. It sure didn't feel like it locked though. I wonder if the PWM is bad? I might just replace it to be on the safe side unless someone has suggestions. I did talk to a buddy that is a tranny guy, and he said he can't remember the last time he replaced one.
During the time that TCCMODE shows locked and TCCDC shows 99.2%, TSTATE00-TCCESOL shows Off (i.e. TCC was not commanded)... and TCCSLIP doesn't drop to zero during this time.
If you changed the ring/pinion ratio, did you correct the speedo and apply the correction to the shift tables (which includes the TCC apply/release tables)...?
Yes I changed all the tables. It did lock up properly for a while (about 400 miles), then just stopped. I went WOT at about 40 for about 1 full second, and it stopped locking up after that. I was commanding it to lock in 2nd at WOT. Maybe I damaged the clutch in the converter, but I doubt it would do that much damage from briefly going WOT. It really didn't work it too hard, I let off because it was breaking the tires loose.
Last edited by JUSTASBC; May 16th, 2012 at 02:19 PM.
Use the scantool to command lock up while driving (use assistant) to see if the PCM is able to command it.
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