What causes no crank and no start in the 2014 chevy sonic?

Usually if You have a no crank and a no start situation in a 2014 Chevy Sonic that is a sign that the battery is dead. The first thing You should do is check Your battery cables and make sure that they are secure and tight on the battery terminals. Once You know that those are on then You should check the resting voltage. If that is below 12 volts You may not have enough power to turn over the starter motor. It is also possible that there is a problem with the ignition switch in Your car and that may need to be replaced to get it starting again.