Well, we "think" its fixed need to do the flight test in a few days.
What stop the error code was adding to the length of the RG400 coax (about 18" long) from the transponder to the GDL82. Replaced with about 6' of RG58 with a BNC male adapter to connect the two. Tried all different combos but this was the only one to work. Its now about 6' total length, RG400/connector/RG58. So that's the story now, time will tell......