2000 Silverado 1500 4.3 driving me nuts.

Hi, 2000 silveraldo rwd, auto,1500,4.3.  cannot communicate with the bcm. communicates with the cluster,VCM,BCM. mitchall on demand and other DLC pin outs show to check the bus line  is on 6 & 14 on the dlc. on this vehicle there is no wire or pin for #6 on the DLC for the hi bus line. what am I missing here?? I have tried a used known good BCM in it also will not communicate with the BCM, thanks. 

Hey boatmoter! Your Silverado uses a Class 2 network (pin 2 at the DLC) for all module communications. Not sure why Mitchell said anything about DLC pins 6 or 14...

The IPC and the VCM both use the same network, so if your scan tool can talk to them, then the network is at least partially intact. You'll need to check voltage on the Class 2 pin at the BCM and compare it to pin #2 at the DLC, key on engine off. If the voltage is the same, then the network is fine and you have a BCM problem. If the voltage is different, there's a network problem.

Class 2 at the BCM is a green wire, pin A12 of connector C1: