mwolf380

So....the transfer case harness had the second plug off of the VSS in the transfer case that just looped back to the plug that would have plugged into the 2nd VSS on the transmission, had it been there. But as soon as I plugged that plug on the transmission harness to the transfer case harness, the speedometer came to life the abs light went out, and the service brake system message went away. The transmission now shifts properly too. Thank you again for your help. Doing all this work (new engine install, transmission replacement, new fuel lines, etc) all solo I was bound to miss a few things.

Davester, thank you so much, that last post helped so much. I figured out that the plug I have a picture of above went to the plug for the second speed sensor! Plugged in and issue is fixed! Thank you so much again.

So still baffled. However I did discover this plug. Any idea what it's for?

I think you may solved this for me. I will respond tomorrow if that is the case.

Ok, this is my first Silverado. I dont have any plugs on the rear of the transfer case. I will have to look again.

The harness in my truck has plugs for both front and rear on the transmission. Also none of the harness is modular, it's all one piece. So there's no 4wd harness per say, it's just part of the engine harness. The truck the used trans came out of was the exact same drive train (engine and transmission) other than being a year newer and a suburban not a silverado.

I have a 2003 Chevrolet Silverado 2500Hd 4x4 with 6.0 LQ4, 4L80e and manually shifted transfer case. Burned up the transmission so I picked up a used 4L80E out of a 2004 Suburban 2500 with the 6.0. Well finally get it installed and during the installation, had 1 plug I could not figure out where it went to. Well after scratching my head for a few days discovered the replacement transmission is missing a speed sensor. Swap it over from the old transmission. Take it for a drive and no speedo. Anyone run into this before?