I did it on my 2000. I repinned the factory 99-02 harness.

 

Honestly after doing this one repining a 0411 harness would've been easier probably. Only reason I didn't is I'm swapping a 99 v6 truck so the harness is totally different.

 

Let me know if you need some help with the programming. It took 3 different segments to get everything to work properly. I build mine off an 04 7603 OS.

 

I did a Tahoe flex os segment swap on the engine/trans/system and modified the system settings to disable dbw and enable dbc then disabled a few codes for dbw and enabled some for the dbc and composition sensor. I use a pcmofnc 60to80 adapter so I can use a 60 segment. I will be starting the swap next weekend.
hopefully it will all work as planned.

 

Sounds like you have it figured out, cool!

You will need to adjust for AC as the P59 uses AC pressure sensor instead of low/high switches in the 99-02. My AC did not work until I changed the settings. In my case, I copied the systems segment from a van, but you can also try to change the settings to analog and cycling in HPT.

 

I did switch the settings but I was curious about that part as it was the only part I wasn't 100% sure on. But that clears it up.

I knew if all else failed I can wire a pressure switch through the ground side of the clutch relay and give it constant hot like I have done before on older sbc swaps I've done in the past. But if it can work like factory I'd rather utilize that.

 

Did you use the van harness and ecu and splice it in with the v6 stuff?

 

I used a van pcm but an 03 Silverado p59 dbw harness

 

I see a couple of you guys have done this so you are obviously more capable than me, I’m wondering if it’s fresh enough in your mind or you documented anything on swapping changing plugs/fuse box wiring on the 03+ Harness to work with the 2000. Or wiring changes needed to use the 2000 harness with the DBC p59 ecm.

 

The plugs are year model specific get a 2003 model harness from a salvage the closer the year to yours the least amount of changes. I did a 2005 harness in a 99 and had to change quite a few wires. I use wiring diagrams from lt1swap.com and look at both year models. I was going to document mine but didn't get a chance to. Get your p59 from a dbc van or a 4.3 van. All the 4.3 vans I've seen are dbc and can be segment swapped to a v8.