I'm hoping that you guys can help me out, as I'm in over my head. As part of a stupid project to put OEM power windows from a 99 LS truck into an 02 W/T, I swapped dash harnesses between the two. I've run into some problems, and I can't go backwards as I have already cut the old harness in several places.

The 99 was a 5.3 4wd truck. The 02 is an 8.1 with the Allison 1000, 2wd, electronic throttle. Although I swapped harnesses, I kept the BCM from the 02 in the 02.


I have no gear indicator lights on the instrument cluster and I have the following codes:
P0700 - TCM malfunction
U1000 - No communication
C0315 - Service 4wd
C0327 - another 4wd error
C0323 - another 4wd error

1. What wire does the TCM use to communicate back to the PCM, BCM, and/or cluster?

2. The dash harness is a 4wd harness but the truck it's in is 2wd, and I kep the 2wd BCM. Why am I getting 4wd codes now? The cluster is flashing Service 4wd.

So here's what I'm working with. I have connectors on both sides that don't have anywhere to plug into.

On the dash harness side, I have these two with no mate. Both of these plugged into the transfer case harness on the 99.



I have these two that fit together. The dash side has 1 more wire than the truck side (looks like it goes to the trans) does.

Pin - Dash side - Truck side
A - Empty - Empty
B - Brown - Brown
C - Lt Blue - Lt Blue
D - Empty - Empty
E - Purple - Purple
F - Tan/white - Empty
G - Empty - Empty
H - Empty - Empty





There's this one that I don't think was plugged into anything in the first place, before I did the swap:


This connector goes into the ECM/TCM harness. There are only two wires that come into it, a yellow one and a purple one. On the original 02 dash harness, I traced the yellow one back to a connector that isn't hooked up to anything, so I don't think that one's an issue. I can't trace the purple on, because like an idiot I cut it along the way.

 

So this harness that your questions are referring to is the duramax harness, correct? So you'd be mixing the original BCM from that truck with the ECM and TCM of the duramax harness?

 

These may be helpful....hopefully. lol

 

This is a different deal. It's the dash harness from the 99 with a BCM, ECM, TCM from an 02 8.1/Allison. I agreed to put the factory power windows and locks in this guy's truck before I knew how much of a disaster this project was going to turn into.

 

Ok, well disregard those first images I posted. I updated the post with the correct diagrams...

 

Thanks! I think I'm getting close...do you have the diagrams for the DLC that is referenced in the 2nd image above?

 

Heres a couple

 

BINGO!!! The yellow class 2 Allison data wire was missing from the DLC connector from the 99 dash harness. WOOHOO!!!!! Thank you!!!

 

So does it work?!

 

Yep