Generally, you don’t have to.

You can sign up for a repeat module examination, provided that you are (still) registered for the module, without signing up for the course again.

Course-related examinations (vorlesungsbegleitende Prüfungen) are special cases. It may be that you have to repeat the course itself before being able to repeat the examination. In this case, you can register for the course in TUCaN via Courses > Registration.

If you are unsure as to whether or not you need to sign up for the corresponding course again, please contact your Office for Student Affairs.