Are you in the market for a new or used vehicle and having difficulty finding something in your budget? Or are you finding yourself making trade-offs to find something you can afford (i.e. less cargo space, lower trim level). A reporter from a national news publication would like to speak with you about your experience; please reach out to PR@Edmunds.com by this Friday, 11/21 for details.
Answers
There is a switch on the gear selector that should trigger a relay to close all door locks at once, not each door lock individually.
Sounds like you driver side power door lock actuator has either a bad electrical connection or has died. Replacement part and/or how to fix here:
https://www.google.com/search?q=cobalt+door+lock+actuator&rlz=1C9BKJA_enUS614US614&oq=cobalt+door+lock+actuator&aqs=chrome..69i57j0l3&sourceid=chrome-mobile&espv=1&ie=UTF-8&hl=en-US