Towing behind motorhome

[acker1]

2107 GMC Sierra 4X4 Crew Cab--I am all set up for towing but have a question. When I disconnect the battery I will lose my settings. I found a thingy that plugs into my OBDII port and other end connects to an outside battery source. That will keep my setting BUT will it affect the electric steering?

Thanks
d**k