All right, I've found a guide to reading K1100 error codes, assuming that they are the same Motronics codes for 4-V K100.
"Thereis a black 3 pin diagnostic connector on the left side of the bike above and to the left of the battery, you will needto remove the side cover to gain access. This connector will have a blue plastic weather protector connected to the open end. Pin #1 will have two Brown/Black wires, Pin #2 will have one Brown/White wire and Pin #3 one Brown/Green wire"
I'm not finding ANY connector on the left side of my battery, and nothing with these wire colors on the right side of the battery. Do I need to remove the petrol tank just to get to these connections?