You can call the IWindows Update Agent Info:: Get Info method to get current version info about WUA, but you can't determine if that version is the latest.
When necessary, to ensure that users have the latest WUA, prompt them to install KB949104 or the latest WUA.
Follow these steps in your app to determine whether or not the running version of WUA is the most recent one (or at least a current one).
(00000000) This log file appears to indicate that no updates are pending, but WSUS clearly shows that there are and that CADCS002 has successfully installed them.
Choosing "Check online for updates from Microsoft Update" works fine.
But even if you know the version of WUA is out of date, you can't use the WUA API to force a self-update.