My slot CD player thinks a CD is inserted when it is not.

What is your question?

The "CD inserted" LED stays on almost all of the time. (When it plays it plays beautifully.) I have been told that it is a dirty sensor as to whether the CD is inserted or not, but I cannot get to the inner workings.

How long has your 2009 Toyota Matrix had this problem?

For months. I have not had time to look into it.