From what I understand, there is no OBD connection similar to a car. Diagnostics are done via the ECU and require; cable to connect ECU to COM tool, COM tool, cable to connect COM tool to PC/laptop, and LS diagnostics software on PC/laptop.
As for the error code, I don't have any information on what this is. I would call your dealer....he should be able to look it up. If you find out, be sure to post it. Would be great to put together an error code list for all of us to refer to.
I do know from personal experience that the limp mode is used in certain safety features to prevent engine damage, such as, overheating.