For some strange reason Google Maps launches on its own. It doesn't launch all the way though. It just leaves a black screen.
Does anyone know why this is happening?
Try Uninstalling and re-installing it.
Clear the app data.
Might be a bug with the custom ROM (ignore if on stock).
As for WHY it is happening, could be a faulty installation IMO, but if the package was faulty, it wouldn't get installed in the first place. Anyhow, just try the above steps.