Did you look up message ICE109A in "z/OS DFSORT Messages, Codes and Diagnosis"? If so, you would have seen this as the first thing in the Programmer Response:
Make sure that the length and position values in the FIELDS operand of the SUM control statement were specified correctly. For BI and FI, length must be 2, 4, or 8 bytes; for PD, length must be 1 through 16 bytes; for ZD, length must be 1 through 31 bytes; ...
You have a BI SUM field with length 5, which is invalid. If your sum field is really BI, then you must use a length of 2, 4 or 8 bytes. If your sum field is some other format, such as ZD (as it appears to be from your example), then you need to use that format instead of BI.