Does location update remain running after force close app

Yep it will continue to be updated when the application is sent into the background. For some official docs check here under the "Getting Location Events in the Background (iOS Only)" section.

Also, under special circumstances you can register your application to have a true background process running like Android allows. So when the user kills the background application, your app doesn't really die. The background process continues to work. Apple will only allow apps that have a necessary reason for this though. Such as a turn by turn navigation app (example from the docs).