I'm sorry to hear about your door lock problem. It's possible a fuse needs to be replaced. The Automatic Door Lock System fuse is located in the instrument panel fuse block.
The instrument panel fuse block is located at the lower front side of the console, on the passenger side of the vehicle. To access the fuses, open the fuse panel door by pulling out.
To reinstall the door, insert the hooks at the front end first, then push the door into the center console panel to secure it.
There is a diagram of the fuse block on page 5-86 and a listing of fuse names on page 5-87 of the owner's manual. For your convenience, a digital copy of the manual is available at: http://www.extendedgmwarranty.com/ow...let-Malibu.pdf
To check the fuse, look at the silver-colored band inside the fuse. If the band is broken or melted, replace the fuse. Be sure you replace a bad fuse with a new one of the identical size and rating.
If this does not resolve this issue, I encourage you to have the vehicle inspected by a certified technician. They will be able to offer additional information after a physical inspection.
I hope this information is helpful. If you have any other questions, please feel free to contact me.
GM Customer Service