data link connector Gen5 info needed

hello all I was not sure where to post this but I am building a stand alone harness for my gen 5 and have most of it sorted out. I am to my obdii connector (data link). What wires do I need to hook my HP Tuners up with? The diagram shows two (1 and 2) GMLAN highspeed plus and minus I was going to run both but my generic connector didn't have enough wires, I can add some but didn't have the right connectors on hand. Can I get by with just hooking up the number 1 GMLAN along with the other 12 volt, ground (serial and other)?
I may also eventually use a CAN bus type gage system but that is down the road.
Thanks a ton.
David

I don't believe that will work. In my experience, CAN bus (at least on all the vehicles I've scanned and flashed) needs the high and low input or it will fail in strange and mysterious ways. I know this first hand because my HPT cable lost pin 6 (CAN high) and wouldn't read any CAN vehicles or my bench harnesses, but it still read all OBD2 serial data (pin 2) PCM's without issue.

Thanks for that, my dealings have been with the Gen 3 motors and they didn't have these additional GMLAN connectors. I was not sure what all was to be used. I will find more connectors an do it correctly unless somebody can add more info. I didn't know if since there were 2 high speed if one was redundant.

You are just trying to build a bench harness?

No I'm retrofitting this engine finishing the harness

Ah gotcha.