IBM 3270 Maintenance Manual page 38

If you press the PFI key, the system unit will
bypass the error and attempt to complete POST.
The completion of POST mayor may not be
possible, depending on the error. If POST is able
to finish, you may be able to load the diagnostics
program. This is very important because many of
the PIes specify that diagnostic testing be done.
Note: If you receive any error indications during
or at the completion of POST, make a note of the
error and then go to the "Start" page in Section
3.
October
1984 2-7