Use program RPDASC00 to expand your Payroll Schema, with all it's sub-schemas.
In the result, search for parameters P03, P04, P20 and P41. You should find at least 2 occurrences of each, once in the Off-Cycle Sub-Schema and once in the "regular pay" sub-schemas.
Note that there are many threads on that transaction (accessible through t-code se38),
as there are many on how to execute a Payroll Simulation with the "Display log" box checked to drill down into the log.