Discovered this forum by doing searches on how to get the door open on my 2006 ss cobalt. I have the door panel off and cannot find anything wrong. I cannot figure out how to manual unlatch the door. Done a search on the forum and found some old post but none has helped me get the door open yet. Hope someone can help.

 

i had a similar issue, here is what i did.

you already have the door panel off. there is a black box where the door latch assembly meets the striker post. move the door lock post manually up and down, if the lock isn't releasing at the latch assembly you handles will not work. i used some spray on white lithium grease to lube mine. if you get it to move, be sure to work some more grease in there to keep it moving freely.

 

With an open palm, bang on the outside portion of the door on the area where the door would latch on to the frame

OR

Manually lock and unlock the door with the stick thingy.. and it'll eventually catch.

I've done both and they both work. Also lube up the assembly.

 

Check the weather stripping it can cause problems they dry rott very easily and cause door to get stuck