Thread: TCC lock up issues after rebuild and new TC

A heads up... I did some driving around today with a MAC Mentor scanner (compared results under TCC Data with my '99 Bonneville SSEI, 4T65E-HD in there as well).

Well, everything looks similar, ISS speed, output speed, slip matches at acceleration, etc.

Only thing I can see that is actually different with the readouts is "TCC Release Press" is always on "YES". It never says "NO" like the other car when lockout is engaging.

So, I am now assuming I have a fluid/hydraulic leak somewhere.. BTW, I have an Overkill PCM w/ updated transmission parameters (modified). I am waiting for a 3rd PCM sometime this week that has stock transmission settings to use as a test to make sure it's not a modded PCM + upgraded transmission that's causing all my woes.

whan i had my car on a scanner everything looked good also except that the TCC duty cycle % was only 40% at its highest, and the reason for this is that the TAPs were never reset after the rebuild. And the extra high trans presures before the rebuild cause the pcm to back off the TCC duty cycle to soften the TCC engagement. when you reset the TAPs it puts the TCC% back to normal, but by this time the damage to a non carbon fiber TCC may already be severe enough to cause no lock up.

I had planned on doing a TAP reset, but I can't seem to figure out how to do it on this scanner. Have any suggestions?? Maybe the wording is different than I am expecting.

It's a Mac Mentor unit.. Pretty nice, but not sure how to fully use it.

Thanks for the heads up.. So, are you now having NO problems after the reset, or did I mis-read???

No it wasnt a fix but it might have contributed to the problem, the Tech2 and snapon scantools can do it. Most pepboys have a scanntool that can do it and they might not charge you if you know exactly what you want to do, if not the dealer can def do it.

I found the root cause of the problem, while my trans was apart today we found that the snapring that secures the drive sprocket to the input shaft had poped off causing the shaft to move back and forth wearing into the sleeve that the input shaft rides in, this caused low apply pressure to the TCC. The reason the snap ring poped off was the groove in the ZZP 4340 input shaft, that the ring rides in was machined incorectly it had a rounded upper lip causng it to pop off.