I have a 2000 carryover 3500 pickup. It looks like a 96'-98' truck. I built a mild 383 with a small camshaft, and ported stock heads. When I first put the engine in the truck, the tcc worked like it was supposed to, but I had a very lean condition due to the engine modifications. Before getting it tuned, I turned up the fuel pressure to help with the lean condition, and ever since, the pcm doesn't command tcc. Thinking it was just going to be a tune issue, and something to do with fuel trim, I had the truck tuned, and now it still doesn't command tcc. After an ignition cycle, it will lock up one time, but none more thereafter. The guy tuning disabled misfire codes, disabled fuel trim codes, and disabled o2 codes. It will lock up when commanded with a tech 2, but not on it's own. I don't know **** about tuning computers, and the guy doing the tuning has never ran into this sort of thing. Any ideas or suggetions? We are using Efi live software.

Thanks!

 

Also, does anyone know exactly what parameters in the pcm will specifically disable tcc?

 

One signal that can disable TCC is your brake switch (switch under dash mounted to brake pedal). In nornal situations, this will command trans to disable TCC to allow trans to release loc-up to slow down. If your switch is sending a constant signal you are braking, your trans will command TCC once after reset but not again until key reset.