73 nova guy

iTrader: (8)

looking for some help. my car has a 5.3 with a 4l80e and i have no tcc lockup the trans works like normal in every other gear but no tcc. i am using efi live and with the commander the converter will lock up. but in normal driving mode it will not go into tcc mode. i need some idea's were to start figuring out this problem. i have went and turned off dtc's that i don't need the only dc's i have are p103/p103 maf codes being the car is speed density the codes are set to non emissions if i place them on not reported the car doesn't run correctly. and p0463 for a fuel level sensor. i cant for see these not allowing the tcc mode.

i have a brake switch signal to the pcm.

any ideas on were to look would be great..

02WHITEWS6

iTrader: (3)

I'm having same issues. Mine is a 4l60e with a yank 3600. When commanded the converter will lock, but not in its own. What is the problem or what to look for?

slow67

iTrader: (2)

Make sure your misfire tables are set correctly. An aftermarket converter with throw misfires (without a code) because it weighs less. If you can lock it up with the scanner, but the tune won't, this is most likely your issue. It happened to me.

johnnyfast

I had same problem with 4l60e. I had to disconnect purple wire goin to brake switch.

garygnu

the lock up solinoid could be bad or sticky.