Hi I'm new here but been following you guys forever. I always try to work on my own car but I don't know how to fix this problem. Every time I lock or unlock the door on the driver side rattles? Any help would be appreciated thanks!

 

What exactly rattles when you lock or unlock? The entire door or a specific spot on the door? Sounds like something has come loose. Do you slam the door or was there some kind of impact?

You'll most likely have to take the door apart after you isolate where the rattle is coming from.

 

The sound rattles when it locks and unlock. The sounds seems to be at the edge of the door in a specific area

 

quick search brings you to a thread that shows you how to take the door panel off:
https://www.scionlife.com/forums/tc-...-removal-9145/

something will probably fall out when you take it off, there isn't anything we can really tell you on what it might be based on what little you've told.