Hello Kemal,
On ABAP side, you can switch on Audit Logs for J2EE_ADMIN users SM19/SM20N to check if there are any connection requests at the ABAP stack that are causing the password to be locked.
On the JAVA side, you can check server0 trace to figure out what is causing the locks. Rather than disabling passwords etc, you are better of finding out which system/rfc/jco rfc etc is causing the password to be locked.
Regards,
Siddhesh