IBM SC34-7012-01 - Manual (Page 177)

When you have corrected the error, you can re-enable the relevant installed
transaction definition to allow terminals to use it. You can also disable transaction
identifiers when transactions are not to be accepted for application-dependent
reasons, and can enable them again later. The CICS Resource Definition Guide tells
you more about the master terminal operator functions.
If logic within DFHPEP determines that it is unsafe to continue CICS execution,
you can force a CICS abend by issuing an operating system ABEND macro. If
DFHPEP abends (transaction abend), CICS produces message DFHAC2263.
Omitting the PEP
The CICS-supplied PEP is provided in the CICSTS41.CICS.SDFHLOAD library. The
CICS abnormal condition program, however, will link to it only if a program
resource definition for DFHPEP is installed. If CICS cannot link to DFHPEP (for
this or any other reason), it sends a DFHAC2259 message to CSMT.
About this task
Chapter 14. Using a program error program (PEP) 165