In MVS, programs should return to their caller with a “completion code.” It is nothing more than a number from 0 through 4095. Many times these code numbers are a multiple of 4.
MAXCC in JCL refers to the highest completion code from any step in a job. You cannot “cheat” and reset this code.
There is no formal requirement for completion codes and MAXCC to be displayed in the JES2 log. Many accounting related system exits will display these values, but it is a capability added in (more often than not) a defined user provided exit routine in MVS called IEFACTRT.
MAXCC is also a reserved word in IDCAMS control statements.
So you can change the MAXCC value through IDCAMS utility.You
check with your jcl .