What do you want to upgrade from? I had a co-pilot and upgraded mine to an auto pilot. Now I want the i-pilot because of the speed control. In increments of .1 instead of .2 and the GPS ability. Still researching. Check with the local warranty repair shops in your area (on MinnKota website). They can tell you what you can or cannot do. Make sure that trolling motors are their business. Not a marine shop. You want someone who does TM full time.
Good luck.
Chuck
From Steve Wunderele - 10-2-84 --"A fishing trip maybe brief, but it's memories are endless."