For local Windows password changes ADSI is used, which connects using SMB over TCP (port 445).
The 'Test System', 'Password Reset', 'Check Password' all function without WMI.
Account Discovery uses WMI to query information from the Windows system.
Restricted Commands and Event Capture also use WMI. "In order to detect and kill processes on Windows®, the DPA connects to and monitors the target system using WMI."
In version 2.5.916 a change was made to query the target system's name before attempting to change an account password. This was compared with the computer name specified in TPAM.
In version 2.5.918, this change was reverted and the computer name verification is no longer performed.