Comment by jeroenhd
American carriers have a different protocol than the EU. The EU (and probably EU derived networks) uses a """secret""" SMS format that's opt-in, but the 911 system works differently.
The 911 feature can be activated fully remotely, the 112 feature is supposed to only activate when dialing an emergency number.
The US one is called E911: https://en.wikipedia.org/wiki/Enhanced_911