Hey guys, as the title says, I bought a 2006 silverado 2500hd 6.0 4L80..
It has 4.10's as factory and @65mph its doing a bit over 2550rpms at 4th gear with 32" tires, the snap on scanner versus or however it's called, its showing the torque converter not locking, and 0 duty at any point or shift.. Anybody had that happen before?
The mechanic even flashed the computer to factory settings and is still doing the same..
Any idea??
Thanks in advance!

 

Any codes?

 

No codes at all, just the pcm is not sending the lock or unlock signal..

 

I don't know if you tune your stuff or someone else, but there are parameters you need to adjust in the tune for misfire detection. They can prevent a converter from locking up...probably where I'd start.

 

I thought the only time the tc wouldn't lockup is if the trans wasn't up to temp.

 

It could be the o-ring on the input shaft took a crap, that can cause the TC to not lock up and not show on a scanner.