You can deactivate the DFM TP by modifying its TP profile. Using the TPMODIFY command in the APPC/MVS administration utility (ATBSDFMU), you can stop the DFM TP from being scheduled and stop new requests for the TP.

The TPMODIFY command lets you change the active status of the DFM TP to NO in the TP profile data set. If the DFM TP is running at the time, then the current and any queued requests are allowed to complete. No new requests, however, are allowed.

  TPMODIFY
   TPNAME(^X'07'001)
   SYSTEM
   ACTIVE(NO)

For more information, see z/OS MVS Planning: APPC/MVS Management.