bajachevy37

ok i have a 2002 chevy silverado 5.3. i did a tranny swap from the 4l60 to the 4l80. the tranny was looked in 3er gear. i had the computer flashed to a 2002 chevy silverado with a 6.0 motor and 4l80 tranny.. doing this let my tranny shift threw the gears fine. the problem i am having now is the truck shifts at 3000 rpms no matter what if im on it or just crusing it, it shifts at 3000. we had to add 2 pin to the computer for the second vss sensor. if you have any idea or have done this please help lol thank

53RUSSELL

iTrader: (9)

post-up your tune so we can take look at it.

bajachevy37

how do you do that.. i had to take it to a guy and have him flash it..

bajachevy37

i just told him 2002 with 6.0 and 4l80 tranny and he showed me this screen on the computer and it said when its shift points are and stuff like that...

Parke10

iTrader: (5)

am i reading this wrong? or do u have a 6.0 tune on a 5.3 engine?

thunder550

iTrader: (70)

Did you change the wire on the round connector?

bajachevy37

yeah that is the same wire diagram i used..you think it could be somthing with that??? but the only thing i had a problem with was it says u... their is no u on the wire diagram so we just did it with v. if that makes sense. pretty much we cut the brown and white wire and connected the white wire that come out of the plug with the brown wire that come from the harness. is that write i dont think we did anything else with the plug. and we ran 2 wire from the computer from the pins it says on their straight to the second iss sensor

bajachevy37

yeah its a 6.0 tune cos the stock computer for a 5.3 does not have any current or anything going threw 2 pins on the stock computer. the 6.0 tune does cos it has the 4l80 in it and thats were you get the second iss sensor connection. truck willl not shift if you dont get that tune. it will stay locked up in third, that is chevys limp mode on that tranny

GMCtrk

iTrader: (27)

You need to be running a 5.3 tune, not a 6.0 tune. But that doesn't sound like the root of your problem. I would re-check your wiring.

bajachevy37

thats what i was thinking. the stock gm computer sends no signal threw 2 wire on the computer... and thats what the picture is of above. the 5.3 never came with a 4l80 tranny so in order for those 2 prongs to work or send a signal threw them it had to be flashed to one that had that tranny in it.. that tranny only came behind a 6.0. but this is what a guy that did this swap told me.. thats what he said but who knows so i dont know.. now that i read that diagram i think we might have messed up with the wiring i think we left a step out.