I downloaded a file made some changes, uploaded and got a write error at 99% mark. The file would not upload, kept getting timer out error. The computer is P59 Silverado. I have a 2000 411 PCM, I disabled VATS and installed the 411 pcm and nothing happens when I turn the key. I then got an 01 Tahoe PCM 411 and same thing. No start condition...not turning over, no fuel prime heard, just the dash lights up.
Can 411 theoretically work on a Gen iii 4.8?

 

Generally speaking a P59 is a dbw throttle, and a 0411 is a DBC. The Vans are exceptions. I don't know if your working on a f body or a swap or a newer truck. If you put a 0411 on say a dbw truck, at minimum you won't have throttle access, and it may not idle, because those idles circuits will be different. That's the biggest problem. The rest should be able to be changed.

 

My 2002 Corvette is DBW and it uses a 411 PCM.

I don't know whether all 411 operating systems are DBW capable, but anything that came in a Corvette should work. Mine uses 12593358 but it might be easier to find 12212156 with whatever transmission type you need.