03A

Explanation
The error occurred during processing of a BISAM
or QISAM CLOSE macro instruction.
A format 2 data set control
block (DSCB), read from a direct access device into virtual storage,
was updated from various fields of the data control block (DCB). 
When an attempt was made to write the updated data set control block
back to the direct access device, an I/O error occurred.
When
the ISAM interface is used to process a VSAM data set, this system
completion code can be accompanied by message IEC251I.  If it is,
refer to the explanation of message IEC251I for information about
the task that ended.

System programmer response
If the error recurs and the program
is not in error, look at the messages in the job log for more information.
Search problem reporting data bases for a fix for the problem. If
no fix exists, contact the IBM® Support
Center. Provide the JCL and the program listing for the job.

Programmer response
Determine the data set for which the problem
occurred and the nature of the problem.
If this system completion
code is accompanied by message IEC251I, respond as indicated by message
IEC251I.
At the time of the ABEND, register 4 points to the
OPEN/CLOSE/END-OF-VOLUME work area.  At X'64' in the work
area is the address of the job file control block (JFCB) whose contents
begin with the 44 character data set name. The address of the unit
control block (UCB), which contains the device address for the data
set, is located and X'230' in the work area.  The address
of the user's DCB which contains the address of the data event block
(DEB) is located at X'238' in the work area.  Correct the
problem with the data set and rerun the job.

Source
DFSMSdfp