datalink wiring

I've never been able to read the codes off of my car through the datalink. I got into the wiring (again) and today I found the white and black diagnostic enable wire was not connecting to anything. The blue connector under the passenger side kickpanel is where this wire is supposed to make its way through the firewall (I think). On my "IP wire harness" the white/black wire is in slot "c" of that blue connector. Its that way on this harness and on the old harness too. you can see it in shoebox's schematic here http://shbox.com/1/harness_connector_faces.htm The problem is, there is no white/black wire on the small harness that actually makes its way through the firewall. Are there differences in these harnesses? Did the wire get pulled out by a previous owner? I'm at a loss, I don't know where this wire should go now, and it would be really helpful troubleshooting current problems with that datalink working.

I was outside this afternoon looking at the problem and it has really baffled me. From the blue I/P connector (shown in the linkes diagram) the white/black wire does not exist on my car. I pulled the computer today and there is no white/blk wire in any of the 3 connectors to the ecm. Could this have been left out at the factory?

aldl to the computer (http://trumpetsaresexy.com/car/aldl.jpg)

Weird. That wire should be in PCM connector "C" (blue), postion 9.

I know, it really is quite odd. I'm going to have to double check tomorrow but I think the connector on the computer doesn't have a female plug for that wire either. If I can sort this mystery out I'll post the results. Thanks for the great site shoebox. Those pics have saved me a lot of time.